The United States downgraded its diplomatic mission to the Palestinians on Monday, the latest in a series of steps by President Donald Trump's White House Palestinian leaders say is aimed at wiping out their cause.

The move, following a decision announced in October, closes the US Jerusalem consulate general that had acted independently and served as a de-facto embassy to the Palestinians since the Oslo accords of the 1990s.

It will be merged with the US embassy to Israel, where a new Palestinian affairs unit will operate.

US Secretary of State Mike Pompeo says the move will not constitute a change in policy and is intended to improve "efficiency and effectiveness".

The State Department said Monday that "the administration remains fully committed to efforts to achieve a lasting and comprehensive peace that offers a brighter future to Israel and the Palestinians".