Saudi Arabia on Monday rejected US President Donald Trump's decision to proclaim the Golan Heights Israeli territory, saying it "condemned" the move as a violation of international law. 

"Saudi Arabia expresses its firm rejection and condemnation of the US administration's declaration that it recognises Israel's sovereignty over the occupied Syrian Golan Heights," read a statement published by the Saudi state news agency. 

The powerful kingdom is a key Arab ally of the United States, with ties steadily warming since Trump's 2017 inauguration.