US President Donald Trump warned on Tuesday he could sever struggling Argentina’s financial lifeline if his libertarian ally Javier Milei loses crucial legislative elections later this month.

“If he loses, we are not going to be generous with Argentina,” Trump said as firebrand Milei visited the White House to seek the Republican’s political and economic support.

“I’m with this man because his philosophy is correct. And he may win and he may not win – I think he’s going to win. And if he wins we are staying with him, and if he doesn’t win we are gone.”

Trump’s administration has already promised US$20 billion to prop up Argentina’s struggling economy but his backing has failed to calm the markets – or help Milei’s polling ahead of midterms on October 26.

The results of the elections, in which Milei’s minority party is hoping to boost its seat tally, will dictate whether Milei can pass tough cost-cutting reforms or will face a legislative brick wall for the next two years of his term.

Hailing Milei as a “great leader”, Trump said he would “fully endorse” his ideological ally in the elections.