The U.S. approach to Asia faces a major overhaul when Donald Trump takes office, but what will take its place? A new report warns of a leadership vacuum and even a nuclear arms race if the U.S. withdraws from a region threatened by a provocative North Korea.

But authors of the Asia Foundation report provided to Associated Press ahead of its publication Tuesday also say in some parts of the region there's hope that a shift from President Barack Obama's signature foreign policy could be for the good.

The main economic plank of his policy — the Trans-Pacific Partnership — is in ruins. Trump's election victory has erased chances of early U.S. ratification of the trade pact.

Determining what else of Trump's populist campaign rhetoric translates into action remains uncertain.