Britain will seek backing from other United Nations Security Council members on Monday for its demand that Sudan's warring parties stop hostilities and allow deliveries of aid, the British foreign ministry said.

With London holding the rotating presidency of the council, British foreign minister David Lammy is due to chair a vote on a UK/Sierra Leone-proposed draft resolution, which also calls for the protection of civilians.

Lammy will say "the UK will never let Sudan be forgotten" and announce a doubling of Britain's aid to £226-million, according to a statement from his ministry.

A power struggle between the Sudanese army and the paramilitary Rapid Support Forces broke out in April 2023 ahead of a planned transition to civilian rule, killing thousands and triggering the world's largest displacement crisis.

The ministry said Lammy would also criticise restrictions by Israel on humanitarian aid in Gaza and call for an immediate ceasefire along with the release of all hostages.

On the war in Ukraine, he was due to say that Britain "will keep standing with Ukraine until reality dawns in Moscow". He was due to speak to media with Ukrainian Foreign Minister Andrii Sybiha.