Former Vice President Joe Biden dropped a heavy hint that he'll challenge President Trump for the White House in 2020 by saying he was not an aspiring candidate "at this point."

Biden has previously made little secret of his contempt for Trump, saying: "If we were in high school, I’d take him behind the gym and beat the hell out of him." For his part, Trump has said he'd relish a Biden challenge, mocking him as "Crazy Joe Biden" who "would go down fast and hard, crying all the way."

Asked at a London event whether he was was the best alternative to President Trump’s foreign policy agenda, Biden dodged the question by saying any potential Democratic candidate would have “a much more enlightened foreign policy” than Trump.

[Opinion: A preview of Biden 2020]

"I think there are many people in the Democratic Party that can defeat Trump and not a single aspiring candidate that I can think of for the nomination — and I am not one at this point — does not have a better understanding and formulation of American foreign policy than President Trump," Biden told the foreign affairs think tank Chatham House.

"I'm not being rankly partisan here — the president acknowledged at the outset he didn't know a lot about foreign policy. He said he watched the news, although I think he's getting more and more informed out of necessity," he continued, according to CNN.

"I think there are any number of potential candidates seeking the nomination from [California Sen.] Kamala Harris to a whole range of people in my party who would pursue a much more enlightened foreign policy than the president."

Biden has reportedly given himself a deadline of January to determine if he’ll run for president. “I’d love to have it be Biden,” Trump has said. At a Kansas rally last week, Trump branded the former vice-president "Sleepy Joe."

[Joe Biden: 'God forgive me' for staying quiet about Trump for so long]