Corneille Nangaa, who heads an alliance of rebel groups that includes the M23, said their ultimate aim was to topple President Félix Tshisekedi’s government.
Unconfirmed reports say the Rwanda-backed rebels are currently advancing towards Bukavu, the second-biggest city in the mineral-rich east, despite international calls for a ceasefire.
In a televised address after the fall of Goma, Tshisekedi said a “vigorous and coordinated response” was under way to recapture territory from the rebels. 
“Be sure of one thing: the Democratic Republic of Congo will not let itself be humiliated or crushed. We will fight and we will triumph,” he said on Wednesday evening.
The fighting has forced about 500,000 people from their homes, worsening an already dire humanitarian crisis, according to the UN.
On Thursday, Nangaa presented the rebels as the new administrators of Goma, telling journalists they were there to stay and would get services up and running again.
Since fighting escalated last week, electricity and water supplies in the city have been cut off, and food is scarce.
“We will continue the march of liberation all the way to Kinshasa,” Nangaa added.
Analysts say such an offensive would be unlikely given the vast size of the country – Kinshasa is 2,600km (1,600 miles) away. However, it did happen in 1997, when Rwanda-backed forces ousted long-time leader Mobutu Sese Seko.
Nangaa’s comments will increase anger in Kinshasa, which has accused neighbouring Rwanda of backing the rebels, and even having its troops in Goma.
Rwanda is also facing a chorus of international criticism, despite its denials of direct military support.
M23 – the main rebel group in the alliance – is led by ethnic Tutsis, and says it took up arms to protect the rights of the minority group in DR Congo.
Rwanda’s President Paul Kagame is also a Tutsi, and accuses DR Congo’s government of harbouring Hutu militias who were involved in the 1994 genocide in Rwanda.
Credit: BBC News
