Republican President Donald Trump said on Sunday he was not joking about seeking a third presidential term, which is barred by the U.S. Constitution, but that it was too early to think about doing so.

Trump, who took office on January 20 for his second, non-consecutive White House term, has made vague allusions to seeking a third one but addressed it directly on Sunday in a telephone interview with NBC News.

"No, I'm not joking. I’m not joking," Trump said, but "it is far too early to think about it." "There are, there are methods which you could do it, as you know," he said. He declined to elaborate on any specific methods.

U.S. presidents are limited to two four-year terms, consecutive or not, according to the 22nd Amendment of the U.S. Constitution.