ABOARD AIR FORCE ONE (AFP) - US President Donald Trump said on Thursday (Sept 14) he had not yet decided who will be the chairman of the Federal Reserve come February, but said he "likes" incumbent Janet Yellen.

"I do respect chairman Yellen a lot. I like her and I respect her but I haven't made that decision yet," Trump said, giving the clearest hint yet that he could keep the 71-year-old on.

Yellen's current four-year term as Fed chair expires in February.

"I think the country is doing well," Trump added.

"There's a big reason for that and the reason happens to be Trump."

In a speech last month, Yellen strongly defended banking safeguards put in place after the 2008 financial meltdown, which though simply repeating her previously-stated position, was seen as a warning to the Trump administration that may have caused her to lose favour.

Rumours have swirled that Trump could appoint aide and form Goldman Sachs executive Gary Cohn, although senior administration officials have recently scotched that notion.