The Honduras president, Xiomara Castro, has said she has instructed her foreign minister to establish official relations with China, a move that would end its ties with Taiwan and further isolate the island on the world stage.

The Central American country’s switch from Taipei to Beijing would leave Taiwan with formal diplomatic ties with only 13 countries.

China does not allow countries with which it has diplomatic relations to maintain official ties with Taiwan.

Castro, who made the statement on Twitter on Tuesday, had raised the idea of cutting ties with Taiwan and starting relations with China during her electoral campaign. In the tweet on Tuesday, Castro said the decision was “a sign of my determination to fulfil the government plan and expand borders”.

The move comes weeks after her government announced it was negotiating with China to build a hydroelectric dam called Patuca II.

On Wednesday, Taiwan’s foreign ministry said it had expressed “serious concerns” to the Honduran government over Castro’s announcement, urging the country to carefully consider its decision and “not fall into China’s trap” and destroy the long-term friendship between the two nations.

“Taiwan is a sincere and reliable ally. Our country has always assisted Honduras in its national development to the best of our capabilities. China’s only goal in developing relations with Honduras is to shrink our country’s international space, it has no sincere intentions to cooperate for the good of the Honduran people,” the ministry said in a statement.

China’s foreign ministry welcomed the move, saying that it would develop “friendly and cooperative relations” with Honduras.

The Honduran foreign minister, Eduardo Reina, said the decision was about “pragmatism, not ideology” and was motivated by the country’s debt.

Reina said Honduras had needs in energy, social policies and servicing its debt, which were “drowning the country”.

He said Honduras paid $2.2bn last year and must pay another $2.3bn this year for its external and internal debt, which totals $20bn.

Reina added that “171 countries in the world have relations with continental China” and the economic reality was that Honduras “had to take that decision”.

“The idea is to look for mechanisms for greater investment [and] commerce,” he added.

Reina told local television that Honduras intended to keep trade ties with Taiwan.

According to Taiwan’s ministry of foreign affairs, it has diplomatic relations with Eswatini, the Holy See, the Marshall Islands, Nauru, Palau, Tuvalu, Belize, Guatemala, Haiti, Paraguay, Honduras, the Federation of Saint Christopher and Nevis, St Lucia, and St Vincent and the Grenadines.

Latin America has been a source of tensions between Beijing and Taipei.

Aligned with Washington, all Central American countries had maintained ties with Taiwan for decades. But with Honduras switching to Beijing, now only Guatemala and Paraguay have formal relations with Taipei. Paraguay’s opposition says it will switch ties to Beijing if it wins the election in April.

Over the past decade or so, Costa Rica, in 2007, Panama (2017), El Salvador (2018) and Nicaragua (2021) severed ties with Taipei and established relations with Beijing, which had for years lobbied Taipei’s diplomatic allies.

China has also been accused of using bribery to achieve its diplomatic aims. Last week the outgoing president of Micronesia, David Panuelo, accused China of “political warfare” in its attempts to prevent the Pacific country from switching ties from Beijing to Taipei.

Timothy Rich, an analyst at Washington-based thinktank the Global Taiwan Institute, said the “substantive effects” of Honduras switching ties from Taipei to Beijing “should be limited assuming Taiwan avoids kneejerk reactions”.

“Taiwan cannot compete on aid packages alone and should not myopically focus on formal diplomatic partners that cannot aid its economic or security concerns,” Rich said.

The move by Honduras comes ahead of theTaiwan president Tsai Ing-wen’s planned trip to Central America next month where she is expected to visit Guatemala and Belize. More sensitively, she is to transit the US and meet the House speaker, Kevin McCarthy, which is likely to anger China.

China sees Taiwan, a self-ruled democracy run independently from Beijing, as a renegade province that must “unify” with China and has not ruled out the use of force against the island. Beijing reacts aggressively to attempts by governments to engage with Taipei, lashing out at diplomatic delegations to Taiwan.

The latest diplomatic moves come amid growing concerns by the US and its allies over a potential Chinese invasion of Taiwan. The People’s Liberation Army sends daily military sorties across the Taiwan Strait to wear down Taiwan’s military, in what analysts have called “grey zone warfare”.

China flew 28 military planes across the Taiwan strait on Wednesday morning, 16 of which crossed the median line, an unofficial border dividing the two shores, according to Taiwan’s ministry of defence.