The government in the Democratic Republic of Congo says the East African regional force has been unable to restore peace in the east of country and must leave by December.

"They have not been able to resolve the problem," government spokesman Patrick Muyaya said on Monday.

The M23 rebels had refused to withdraw from the areas under their occupation in accordance with agreements signed in Luanda, Angola, last year, he said.

A meeting of the regional East African Community (EAC) heads of states “should rule on the incapacity of the regional force” to deal with the issue, he added.

Since last November, troops from Uganda, Burundi, South Sudan and Kenya have been deployed as part of the EAC force to restore peace in the troubled North Kivu province.

The mineral-rich region has been mired in conflict for at least two decades, with different armed groups operating there despite the presence of UN peacekeeping forces since 1999.

Last year, EAC leaders ordered the M23 to cease fire and withdraw to Mount Sabinyo, on the DR Congo side of the border with Uganda.

The M23 stopped their withdrawal in April after Congolese President Félix Tshisekedi excluded them from talks.

Mr Tshisekedi, who is seeking re-election in December, recently called on the large UN force to begin leaving this year instead of next year as initially planned.