Donald Trump has said said he is "not joking" about trying to serve a third term in the clearest sign yet he is mulling ways to breach a constitutional limit against leading the US after his second term ends. He told NBC News on Sunday: "I'm not joking... There are methods which you could do it."

He also said it was far too early to think about it. His current term is due to end in 2029. The 22nd Amendment says "no person shall be elected to the office of the President more than twice".

It was added to the Constitution in 1951 after President Franklin D. Roosevelt was elected four times in a row.

NBC's Kristen Welker asked Mr Trump if one potential avenue to a third term was having Vice President JD Vance run for the top job and then pass the baton to him.

Mr Trump replied: "Well, that’s one. But there are others too. There are others." Asked to suggest another, he said: "No."

The President, who would be 82 at the end of his second term, was then asked whether he would want to keep serving in "the toughest job in the country" at that point.

He answered: "Well, I like working." Mr Trump suggested Americans would support a third term because of his popularity.

Mr Trump falsely claimed to have "the highest poll numbers of any Republican for the last 100 years".

Gallup data shows President George W. Bush reached a 90% approval rating after the attacks on September 11, 2001. His father, President George H.W. Bush, hit 89% after the Gulf War in 1991.

Meanwhile, Mr Trump has so far seen a rating high of 47% in Gallup data during his second term, despite his claims to be "in the high 70s in many polls, in the real polls".

He has mused before about serving longer than two terms, but these tended to be apparent jokes to friendly audiences.

The leader of the US asked a House Republican retreat in January: "Am I allowed to run again?"

It recently emerged that a 1999 Minnesota Law Review article exposed an apparent loophole in the 22nd Amendment.

The paper argues that the amendment has been subject to "widespread misunderstanding" and the idea of a president being banned from a third term is "decidedly incorrect".