Argentinian negotiators representing the government of the climate science denier Javier Milei have been ordered to withdraw from the Cop29 summit after only three days, adding to concerns about the stability of the Paris agreement.

More than 80 representatives from the South American country are in Baku, Azerbaijan, for two weeks of negotiations about climate finance for the energy transition. Argentina’s far-right leader has previously called the climate crisis a “socialist lie”, and threatened to withdraw from the Paris agreement during his election campaign last year, but has since backed down.

On Wednesday, representatives from Milei’s government were ordered to leave the Azerbaijani capital. Speaking to the Guardian, Argentina’s undersecretary for the environment, Ana Lamas – the country’s most senior representative on the climate and nature after Milei dissolved the environment ministry – confirmed the decision first reported by Climatica.

“It’s true. We have instructions from the ministry of foreign affairs to no longer participate. That’s all I can tell you,” she said. Lamas said the decision applied only to Cop29 when asked if Argentina was planning to leave the Paris agreement.

There is widespread concern about the future of the climate accord after the election in the US of Donald Trump, who has pledged to exit the agreement for the second time. Before the talks, the UN secretary general, António Guterres, said a second US departure might “cripple” the global deal to limit heating to below 2C above preindustrial levels.

There are fears that other countries may leave the international climate agreements, including countries such as Argentina that are led by climate deniers. On Tuesday, Milei spoke with Trump, after which Milei’s spokesperson said Trump told his Argentinian counterpart that he was his “favourite president”.

The climate change management specialist Carla Chavarria said Argentina’s decision to withdraw from Cop29 talks would be bad for its future.

“Argentina withdraws its delegation from Cop29 in Baku, losing its voice in climate finance negotiations. At a key moment to secure resources against the climate crisis, the country is left out, weakening its future and its ability to adapt,” she said on X.

“We participated in the negotiation group on the gender program in the climate change convention with [Argentina’s representative]. It is sad to see Argentina’s absence from the negotiations after having led on this issue in many of the previous Cops,” said the Citizens Association for Human Rights, which is present in Baku.

Milei’s administration has sought to roll back environmental rules to drive economic growth since he became president last year, including relaxing rules about protections for forests and glaciers.

Julieta Zelicovich, a professor of international relations at the Universidad Nacional de Rosario, said Wednesday’s decision was a bad sign for a trade pact between the EU and South America’s Mercosur bloc.

“Without environmental commitments, any possibility of announcing an agreement at the G20 collapses. If the government wanted to move forward on trade agreements, this is a very wrong step,” she said.

Oscar Soria, the Argentina director of the Common Initiative thinktank, said: “Argentina’s decision to leave the Baku talks is a sharp departure from its traditional climate policy, not a surprise under Milei’s government, who have pressured Argentine diplomats to take untenable positions in the past.

“This decision is purely ideological and goes against the best interest of the country, whose economy was severely impacted by the climate crisis. Like in other instances, such as the decision of Argentina to leave the Summit of the Future last September, this is yet another sign of an unhinged far-right policy that uses high-profile moments as a burlesque show for the pleasure of the global far-right movement.”