Rwanda-backed rebels who have captured eastern Congo’s largest city say they plan to take their rebellion to the capital and seek to gain political power.

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.

By Yassin Kombi and Sonia Rolley GOMA, Democratic Republic of Congo (Reuters) -President Paul Kagame said Rwanda was ready for "confrontation" as he rejected criticism over his backing for M23 rebels who were pushing south on Thursday in eastern Democratic Republic of Congo after capturing the major city of Goma.

A conflict that has raged for decades reached a flashpoint this week when rebels backed by Rwanda marched on a key Congolese city in a bid to occupy territory and exploit minerals.

As an East African bloc urged an immediate ceasefire in eastern Democratic Republic of Congo, Rwandan-backed M23 rebels who seized the city of Goma extended their advance on Wednesday, and Congo said it planned a campaign to recover lost territory.

After a lightning offensive, M23 rebels now control Goma, a large city in the eastern Democratic Republic of Congo.

By Yassin Kombi and Sonia RolleyGOMA, Democratic Republic of Congo (Reuters) - Rwandan President Paul Kagame blasted criticism of his country's role in eastern Democratic Republic of Congo where rebels his government backs have seized its largest city,

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.

Rwanda's ally Uganda, unhappy about another rebel group in DR Congo that threatens its security, has also been accused of helping the M23 - with its officers also spotted at Tchanzu. The UN experts say Uganda has also supplied weapons, hosted rebel leaders and allowed cross-border movements of M23 fighters - accusations Kampala denies.

Congo's security forces are fighting against Rwanda-backed rebels who advanced into a key eastern city in a major escalation of a decadeslong conflict.

Rwanda-backed rebels claimed on Monday they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped.