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House and Senate Republicans are doubling down on their commitment to investigate the decisions leading to President Biden's "disastrous" Afghanistan withdrawal, but Democrats are shying away from publicly blaming Biden and his administration.

Secretary of State Antony Blinken appeared at two heated hearings before the House and Senate foreign relations committees this week, during which he defended the actions of the Biden administration and its decision to withdraw all U.S. troops by Aug. 31, leaving behind thousands of Americans, green card holders and Afghan partners. 

House Foreign Affairs Committee Ranking Member Rep. Michael McCaul, R-Texas, told Fox News on Friday that Blinken did not adequately defend the administration's decisions during the hearing and renewed his vow to continue to uncover how the "tragedy" of the Afghanistan withdrawal unfolded.

BLINKEN HEARING: DEMOCRATS RUSH TO DEFEND BIDEN'S DEADLY AFGHANISTAN WITHDRAWAL

"As the entire House Foreign Affairs Committee saw in this week’s hearing, Secretary Blinken struggled to defend the haphazard decisions that he and President Biden made that led to the disastrous Afghanistan withdrawal. This week I announced that Committee Republicans hired an investigator to join our team as we look into this systemic failure, and I hope that we are able to work together to come to an accurate conclusion and determine how this absolute tragedy could have been avoided," McCaul said.

The Texas congressman announced Tuesday that he hired an investigator to look into Biden's withdrawal, calling it a "systemic failure" by the federal government. That investigator is Ryan Browne, who worked as a CNN reporter from 2015-2021, according to the House Foreign Affairs Committee.

Alternatively, Democrats on the House panel have slammed critics of Biden and shifted blame off the administration for its deadly withdrawal. 

"Disentangling ourselves from the war in Afghanistan was never going to be easy," House Foreign Affairs Committee Chairman Rep. Gregory Meeks, D-N.Y., said during Monday's hearing with Blinken. 

Meeks, the leading Democrat on the committee, also repeatedly slammed Biden’s critics during the hearing and attempted to shift blame to former President Donald Trump's administration, suggesting he would like to hear from former Trump officials, as well as decision makers from the Obama and Bush years. A spokesperson for Meeks declined Fox News' request for comment for this report.

BLINKEN TAKES BIPARTISAN CRITICISM, DEFENDS AFGHANISTAN WITHDRAWAL DURING SENATE HEARING

Senate Republicans are also working to hold other Biden administration officials accountable. So far, Blinken has been the only cabinet-level official to testify publicly on Capitol Hill since the withdrawal and there are many questions from lawmakers that remain unresolved.

Senate Foreign Relations Committee Ranking Member Jim Risch, R-Idaho, said he will continue to call on Biden administration officials to testify, including Defense Secretary Lloyd Austin, who has previously declined the committee's invitation.

"Congress has a vital oversight role to play with the disastrous withdrawal from Afghanistan. To get to the bottom of what went wrong and prevent a similar tragedy from happening again, we must have administration officials testify, including Secretary Austin who has refused to come before the Senate Foreign Relations Committee. The debacle in Afghanistan is an interagency failure, and we must hear from all relevant officials in order to hold the right people accountable," said Risch in a statement to Fox News.

Jim Inhofe, R-Okla., the ranking member for the Senate Armed Services Committee, said the committee will be undertaking a "methodical review" of Biden's "disastrous" decision and will be continuing to ask for open hearings with top Pentagon officials.

"This is just the beginning. I expect the Armed Services Committee will have many hearings and briefings on the topic. The American people, our service members past and present, our allies and partners around the world and the Afghans who bravely helped us deserve this transparency and accountability. We have a lot of questions, and we’re going to keep asking for hearings until we have all the answers," Inhofe told Fox News.

Senate Foreign Relations Committee Chairman Bob Menendez, D-N.J., called the Afghanistan withdrawal "fatally flawed" during a committee hearing with Blinken earlier this week, but he did not reply to Fox News' multiple requests for comment Friday about whether the committee will commit to continuing to bring in Biden administration officials to testify.

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Menendez did echo disappointment that Austin did not accept the committee's invitation to appear alongside Blinken at the hearing.

Fox News' requests for comment to House Armed Services Committee Chairman Rep. Adam Smith, D-Wash., and Senate Armed Services Committee Chairman Sen. Jack Reed, D-R.I., were not returned.

Fox News' Lucas Y. Tomlinson contributed to this story.