Colombia's president on Tuesday said he intends to sign an accord to join Beijing's Belt and Road Initiative during an upcoming China trip, a move sure to damage already frayed relations with Washington.

Leftist leader Gustavo Petro said he would sign a "letter of intent" to join the pact when he meets his Chinese counterpart Xi Jinping face-to-face in the coming days.

The Belt and Road Initiative is a central pillar of Xi's bid to expand his country's economic and political clout overseas.