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Salvadoran authorities on Tuesday denied having asked Taiwan for money in exchange for maintaining diplomatic relations with the self-governing island, saying its decision to switch recognition to China was due to the enormous advantages of trading with the economic giant.

In an interview with state television, presidential spokesman Roberto Lorenzana called Taiwan's allegations "base" and "totally false," noting that other countries have opted to have diplomatic and commercial relations with Beijing.

"We cannot turn our back on the world, ignore that China is the second largest power in the world and the leading export economy on the planet," Lorenzana said. "It is key for our country."

President Salvador Sanchez Ceren announced Monday night in a televised address that his country would break from more than 80 years of relations with Taipei and immediately switch to Beijing.

China considers Taiwan a renegade province, and the two have long competed with so-called dollar diplomacy — funding public works projects such as stadiums, for example — to secure recognition from other nations. With El Salvador's switch, 16 small countries plus the Vatican currently recognize Taiwan.

The move prompted the U.S. Ambassador to El Salvador, Jean Manes, to tweet late Monday that the decision "is worrisome for many reasons" and "without doubt this will impact our relationship with the government."

Florida Sen. Marco Rubio threatened to block funding for El Salvador, accusing it of being "against the U.S. on everything."

"Why should we keep sending them so much foreign aid? Today I will begin work to end that," Rubio said via Twitter.

The United States formally recognizes only China, but it maintains a de facto embassy known as the American Institute in Taiwan. Taipei has a similar quasi-diplomatic outpost in Washington.

El Salvador's decision also drew criticism from the domestic opposition.

"The position from Taiwan is that the government of the FMLN (Sanchez Ceren's political party) asked it for money to finance the campaign in 2019," said lawmaker Margarita Escobar of the conservative Arena party. "That is called selling sovereignty and allowing another state to intervene in the internal affairs of El Salvador."

"I do not support this erroneous decision," said Guillermo Gallegos of the Grand Alliance for National Unity. "I would qualify it as sad and regrettable."

Sanchez Ceren said in his address that the decision came after "a careful analysis" and "will bring great benefits for the country, and will open up extraordinary opportunities."

He said three high-ranking Salvadoran officials were in Beijing to sign an accord on establishing diplomatic relations.

Taiwanese Foreign Minister Joseph Wu accused China of luring away Taiwan's allies with promises of vast financial aid and investment.

Wu said Tuesday that El Salvador had repeatedly sought large amounts of funding from Taiwan for a port project that a Taiwanese team of engineers dispatched by the government thought wasn't economically feasible.

Norman Quijano, a legislator from the conservative Arena party and president of the country's congress, called the move "a betrayal of a friendly country."

In a statement, the party warned that it could have geopolitical consequences including "with strategic allies such as the United States."

The U.S. is El Salvador's largest commercial partner and also home to an estimated 2 million Salvadoran migrants, including people in the country legally and illegally. In January the Trump administration announced an end to temporary protected immigration status for about 195,000 Salvadorans, and the Central American country has hoped for legislation that would allow them to stay beyond a September 2019 deadline to leave.

Panama switched recognition from Taiwan to China in 2017, and the Dominican Republic did the same earlier this year.

Taiwan split from mainland China amid civil war in 1949, and China considers the island its territory.