Reuters, Washington
US President Donald Trump is willing to hold a summit with the leaders of Russia, China, Britain and France - the five permanent members of the UN Security Council - to discuss arms control, a senior administration official said on Friday.

Trump wants to use the meeting to try to make progress on a three-way arms control deal with Russia and China, the official said. The timing for a summit was unclear.

"The United States will use this opportunity to bring both Russia and China into the international arms control framework and head off a costly arms race," the official said, speaking on condition of anonymity.

Trump has sought to persuade China to join the United States and Russia in talks on an arms control accord to replace the 2010 New START treaty between Washington and Moscow that expires next February.

China has rejected Trump's proposal.

New START maintains the only remaining limits on US and Russian nuclear deployments. Some experts and lawmakers have called Trump's proposal to include Beijing in a new treaty a "poison pill" strategy aimed at killing New START and ending the restraints on US deployments.

It can be renewed for up to five years if both sides agree. Moscow has offered to immediately extend the treaty. Washington has yet to decide.

China is estimated to have about 300 nuclear weapons.