Washington, Feb. 6 -- US President Donald Trump has rejected a proposal from Russian President Vladimir Putin to voluntarily continue observing limits on strategic nuclear weapons following the expiration of the landmark new Strategic Arms Reduction Treaty (START).

The development came as Thursday marked the end of the pact, which had imposed the final remaining restrictions on the nuclear arsenals of the United States and Russia, the two nations possessing the world's largest stockpiles, leaving, for the first time in over five decades, no legally binding constraints in place.

Responding on his social media platform, Trump criticised the agreement, calling it "a badly negotiated deal by the United States" that was "being grossly violat...