President Donald Trump has said Indian Prime Minister Narendra Modi has agreed to stop buying Russian oil, as the US seeks to put economic pressure on the Kremlin as part of efforts to end the war in Ukraine.

Trump told reporters he had received assurances from Modi that India would halt its purchases "within a short period of time", which he called "a big stop".

The US president has sought to leverage India's purchases of Russian oil in his trade war, but Delhi has so far resisted.