Eight US senators have sent a letter to Saudi Crown Prince Mohammed bin Salman calling on him to fulfill the kingdom's humanitarian commitments to Yemen, and a move has been announced to vote again on a bill to stop military aid to Riyadh.

The eight lawmakers, including prominent Democratic Senator Chris Murphy and Republican Todd Young, said in their letter that Riyadh had provided only a fraction of the amount pledged as humanitarian aid to Yemen.

Murphy and Young are planning a new Senate vote within weeks on a bill they have put forward in recent months to halt US military aid to Saudi Arabia on the back of human rights and the war in Yemen.

It is noteworthy that two of the signatories of the letter had met with bin Salman in the city of Jeddah last Sunday, and discussed with him several issues, including the war in Yemen, and the assassination of journalist Jamal Khashoggi.

Congress and President Donald Trump have repeatedly wrestled over the administration's support for Riyadh and arms deals for Saudi Arabia and the UAE.

In July, Trump overturned three congressional resolutions to halt multi-billion dollar arms sales to allies, including Riyadh and Abu Dhabi.

In a letter to the Senate justifying his use of the presidential veto, Trump said the decisions "weaken the international competitiveness of the United States and damage the important relations we share with our allies and partners."