Russia vetoed a United Nation resolution Monday calling for an immediate cease-fire between Sudan's warring parties and the delivery of humanitarian aid to millions of Sudanese.

Russia was the only Security Council member that voted against the cease-fire resolution.

China, Russia's ally, supported the resolution, drafted by the United Kingdom and Sierra Leone.

Russian Deputy U.N. Ambassador Dmitry Polyanskiy told the council that Moscow vetoed the resolution because Sudan's government should be "solely" responsible for what happens in Sudan.

U.S. Ambassador Linda Thomas-Greenfield said, "It is shocking that Russia has vetoed an effort to save lives, though perhaps it shouldn't be."

She added, "For months, Russia has obstructed and obfuscated, standing in the way of council action to address the catastrophic situation in Sudan and playing ... both sides of the conflict, to advance its own political objectives at the expense of Sudanese lives."

British Foreign Minister David Lammy said, "One country stood in the way of the council speaking with one voice. One country is the blocker. One country is the enemy of peace. This Russian veto is a disgrace, and it shows to the world yet again, Russia's true colors."

Polyanskiy accused the Security Council of operating under a double standard, pointing to the council's failure to rein in Israel with what he said are violations of humanitarian law in Gaza.

War broke out between Sudan's military and the paramilitary Rapid Support Forces in April 2023, in the capital, Khartoum, just before the country was set to transition to civilian rule. The violence has spread to other regions around the country.

Eleven million people in Sudan have been displaced and half of the country's population, an estimated 25 million people, are struggling with crisis-level food insecurity, according to the United Nations. Famine was confirmed in August in the northern part of Sudan's Darfur region.

Some information in this report came from the Associated Press and Reuters.