FIRST ON FOX: Republicans on the House Homeland Security Committee are warning that the safety of Americans who remain in Afghanistan is "in the hands" of the Taliban’s new interior minister, Sirajuddin Haqqani, the head of a designated terror organization and one of the FBI's most-wanted terrorist operatives. 

The top Republican on the committee, Rep. John Katko, and the top Republican on the House Subcommittee on Intelligence & Counterterrorism, Rep. August Pfluger, wrote a letter to Homeland Security Secretary Alejandro Mayorkas, first obtained by Fox News, laying out their concerns after the Taliban announced the formation of its new government in Afghanistan – including Haqqani as interior minister. 

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"As you are aware, the ongoing crisis in Afghanistan continues to pose increased terrorism risk to Americans both at home and abroad," they wrote to Mayorkas. 

"With American citizens and our Afghan allies awaiting permission from the Taliban to leave the country on chartered flights – a previously unthinkable scenario that is wholly unacceptable to the American people – we are urgently concerned about the Taliban’s naming of one of the FBI’s most-wanted terrorist operatives, Sirajuddin Haqqani, head of a terrorist group known as the Haqqani network, as the country’s acting interior minister," they wrote. 

Further, Katko and Pfluger warned that individuals serving as interior ministers often hold authorities "related to policies governing security, border enforcement and transportation," saying that they are "concerned that the safety of American citizens may now be directly in the hands of a known terrorist operative." 

Biden administration officials said this week that "just under" 100 Americans remain in Afghanistan. The State Department, on Monday, touted the safe evacuation of four American citizens from the country – without interference from the Taliban. 

The Biden administration completed a full withdrawal of U.S. troops from Afghanistan on Aug. 31, after airlifting more than 124,000 Americans and Afghan allies to safety following the Taliban's swift takeover of the country. Administration officials have said the mission has shifted from a military one to "diplomatic," maintaining that they are working with Americans still in Afghanistan to get them out of the country. 

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"We are concerned that this newfound power in the hands of the Haqqani Network may further exacerbate circumstances leading to Afghanistan becoming a terrorist safe haven, accelerating plotting against the United States emanating from Afghanistan," they wrote. 

Haqqani leads the Haqqani network, which has been designated by the U.S. government as a Foreign Terrorist Organization since 2012. The Office of the Director of National Intelligence describes the network as "a Sunni Islamist militant organization" that is "responsible for some of the highest-profile attacks of the Afghan war."

"The Haqqanis are considered the most lethal and sophisticated insurgent group targeting U.S., Coalition, and Afghan forces in Afghanistan," according to the DNI report. "They typically conduct coordinated small-arms assaults coupled with rocket attacks, IEDs, suicide attacks and attacks using bomb-laden vehicles."

U.S. officials have blamed the Haqqani network for numerous high-profile attacks in Afghanistan, including the 2011 attack on the Kabul International Hotel and a pair of suicide bombings at the Indian Embassy. The group had also attacked the U.S. Embassy in Kabul in 2011 and is blamed for "the largest truck bomb ever built," a 61,500-pound device intercepted by Afghan security forces in 2013.

Haqqani is also known as the head of the Taliban’s military strategy, and was placed in charge of security in Kabul after the militants seized the city last month. His exact age is unclear, but he is believed to have been born in either Afghanistan or Pakistan between 1973 and 1980, according to the FBI, which placed him on its most wanted list and is offering a $5 million reward.

The 'Seeking Information' poster issued by the U.S. Federal Bureau of Investigation for Sirajuddin Haqqani, who is Afghanistan's newly appointed acting interior minister. FBI/Handout via REUTERS    THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY

The 'Seeking Information' poster issued by the U.S. Federal Bureau of Investigation for Sirajuddin Haqqani, who is Afghanistan's newly appointed acting interior minister. FBI/Handout via REUTERS    THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY

His father, Jalaluddin Haqqani, founded their namesake jihadist group and handed over leadership before his death in 2018 at 71.  But in the 1980s, the elder Haqqani was among the U.S.-backed mujahedeen warlords battling a Soviet Union invasion and was a close friend and mentor of the slain al Qaeda terrorist Usama bin Laden, according to the U.S. Director of National Intelligence's Counterterrorism Guide.

Since 2008, Sirajuddin Haqqani has been wanted for questioning in connection with a Kabul hotel bombing that killed six people, including one American. He is also suspected of coordinating and taking part in attacks against U.S. and allied forces in Afghanistan and playing a role in the failed assassination attempt of former Afghan President Hamid Karzai.

He has a long lists of aliases, according to the FBI: Siraj, Khalifa, Mohammad Siraj, Sarajadin, Cirodjiddin, Seraj, Arkani, Khalifa (Boss) Shahib, Halifa, Ahmed Zia, Sirajuddin Jallaloudine Haqqani, Siraj Haqqani, Serajuddin Haqani, Siraj Haqani and Saraj Haqani.

And he’s not the only member of the Haqqani network with influence within the Taliban.

Sirajuddin Haqqani’s younger brother, Anas Haqqani, was freed as part of a prisoner exchange in 2019 that also secured the release of American Kevin King and Australian Timothy Weeks, who had been held hostage by Taliban fighters for over three years. Then he led a Taliban delegation to meet with ex-officials of the toppled Afghan government last month. After the Taliban seized Kabul last month, Haqqani’s uncle, Khalil Haqqani, delivered public remarks at the city’s largest mosque – receiving cheers in response, according to The New York Times.

The Republicans also pointed to the Aug. 26 suicide bombing in Kabul, which took the lives of 13 U.S. service members, saying that with Haqqani having "known ties to al Qaeda, including supporting similar suicide bombing attacks," they "struggle to understand how the Biden administration’s reliance on vaguely articulated ‘over-the-horizon' counterterrorism capabilities will be sufficient in protecting the homeland."

Republicans also pointed to a recent statement made by Gen. Mark Milley, chairman of the Joint Chiefs of Staff, who said "there’s at least a very good probability of a broader civil war and that will then in turn lead to conditions that could, in fact, lead to a reconstitution of al Qaeda or a growth of ISIS or other myriad terrorist groups." 

Republicans went on to demand answers as to how the Department of Homeland Security is supporting diplomatic efforts to evacuate the remaining Americans in Afghanistan and Afghan allies, amid reports that the Taliban is preventing flights from leaving. 

As for those seeking to leave Afghanistan, including Americans, a Taliban spokesperson said individuals have not been able to leave if they do not have proper documentation, but said the creation of the new government would help to better facilitate departures. 

"Regarding the flights, they have to obey our law," Zabijullah Mujahid, the Taliban spokesman, said. "They have to have proper documents and if they don't have documents, we will not allow them to go." 

He explained that individuals "have to have passports, have to have visas, and we have to have an exit stamp on their passports – from now, we've had nothing." 

"Tomorrow, on, we will definitely restart the work of departments and then people will be able to travel abroad," he said. "So, the next few days, people will be able to travel abroad." 

Republicans also asked for any intelligence that DHS has related to the Haqqani network’s operations in Afghanistan and the region, whether the network maintains "external plotting capabilities for terrorist attacks," and if DHS has assessed Haqqani’s appointment to be a signal of a close relationship between the Taliban and terrorist groups. 

"How will DHS navigate potential interactions with a known terrorist on security issues under control of the Taliban’s interior ministry, including interactions pertinent to DHS efforts to help evacuate American citizens and Afghan allies, such as border enforcement and vetting?" they wrote. 

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"What impact does having the Haqqani network ingrained with Afghanistan’s senior Taliban leadership have on DHS’s overall assessment of terrorist threats to the United States?" they added. 

Defense Secretary Lloyd Austin this week admitted that there is "no question" it will be "more difficult to identify and engage threats that emanate from the region" after the full withdrawal of U.S. troops, but said the U.S. is "committed to making sure that that threats are not allowed to develop that could create significant challenges for us in the homeland." 

The Taliban, on Tuesday, formally announced the formation of its new government. The Taliban spokesperson said positions within the government are now in an "acting capacity," but many members of the old guard are part of the new government. 

The government, according to a report by the BBC, will be led by Mullah Mohammad Hassan Akhund, with Taliban co-founder Mullah Abdul Ghani Baradar as deputy. Other appointments include Mullah Yaqoob as acting defense minister and Mullah Abdul Salam Hanafi as a second deputy. 

Despite the Taliban's announcement of its new government, the White House is in "no rush" to recognize them as legitimate.

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"There's no rush to recognition, and that will be planned dependent on what steps the Taliban takes," White House press secretary Jen Psaki said. "The world will be watching whether they allow for American citizens, whether they allow individuals to leave who want to, and how they treat women and girls around the country." 

She added: "I don't have a timeline for you." 

Psaki's comments come after President Biden, on Monday, said recognition of the Taliban government was "a long way off." 

"That's a long way off," he said again. 

The Associated Press contributed to this report.