U.S. President Donald Trump on Thursday described the crisis between Rwanda and Democratic Republic of Congo as a "very serious problem."

In 2012, when M23 rebels appeared poised to seize control of a major city in eastern Congo, western countries suspended aid to put pressure on Rwanda to withdraw its support.

Britain has warned Rwanda that its involvement in an escalating conflict in the Democratic Republic of Congo could jeopardise the over $1 billion of aid it receives every year.

U.S. Secretary of State Marco Rubio called for a urgent cease-fire in the conflict in eastern Democratic Republic of Congo saying Washington was "deeply troubled" by a recent escalation in the fighting.

The call came as the US urged the UN Security Council to consider measures to halt an offensive by Rwandan troops

There was gunfire Tuesday in the eastern Democratic Republic of Congo city of Goma, as the United Nations warned of a worrying humanitarian situation amid clashes between Congolese soldiers and Rwandan-backed rebels who attacked the area and claimed to be in control.

The Council met on Tuesday for the second time in three days to discuss the escalating crisis in the eastern Democratic Republic of Congo.

US Secretary of State Marco Rubio pressed Rwanda for an immediate ceasefire in the Democratic Republic of Congo as he voiced alarm over Kigali-backed rebels entering the key city of Goma.

Congolese security forces have tried to slow the advance of Rwanda-backed M23 rebels who say they have captured Goma after entering eastern Congo’s largest city

The Rwanda-backed armed group M23 vowed on Thursday to march on the DR Congo capital, Kinshasa, as its fighters made further advances in the mineral-rich east of the country. "We will continue the march of liberation all the way to Kinshasa,

Kenya has announced a virtual crisis summit, but Congolese state media says President Felix Tshisekedi will not attend.