U.S. President Donald Trump on Sunday said Russian President Vladimir Putin's offer to voluntarily maintain limits on deployed strategic nuclear weapons "sounds like a good idea."

Last month, Putin offered to voluntarily maintain limits capping the size of the world's two biggest nuclear arsenals set out in the 2010 New START accord, which expires in February, if the U.S. does the same.

"Sounds like a good idea to me," Trump told reporters as he departed the White House, when asked about Putin's offer.