The peacekeeping force in DR Congo is the UN's largest
The United Nations Security Council has voted to send 3,000 more troops to the Democratic Republic of Congo following renewed fighting in the country's east.
The increase means the peacekeeping mission, Monuc, will have about 20,000 troops and police on the ground - the biggest UN force of its kind.
But correspondents say diplomats admit they do not know where the troops will come from, or when they will be sent.
The move coincided with a charity appeal to help victims of the fighting.
Clashes between the army and rebels led by Gen Laurent Nkunda have created a humanitarian crisis in recent weeks, with an estimated 250,000 people forced to flee their homes.
The rebels withdrew from positions north of the city of Goma on Wednesday to allow aid into the area. The move came after weekend talks with the UN envoy, Olusegun Obasanjo.
The BBC's Laura Trevelyan at the UN says the Security Council, which first received the request for reinforcements six weeks ago, voted unanimously to send 2,785 more troops and 300 police officers.
Our correspondent says Monuc has been criticised for not doing enough to protect people from Tutsi rebels while the army retreated.
Gen Nkunda has said he is fighting to protect his Tutsi community from attack by Rwandan Hutu rebels, some of whom are accused of taking part in the 1994 genocide.
The Security Council voted for the peacekeepers to implement their mandate "in full", through robust rules of engagement.
Our correspondent says this is supposed to make clear to commanders on the ground that they can use all means necessary to protect the local population.
Earlier, British and international aid agencies launched an appeal for more money to help victims of the conflict.
Charles Badenoch, of World Vision, part of the Disasters Emergency Committee umbrella group, said: "Children are being separated and orphaned by this intense conflict. Thousands of people are vulnerable to rape, malnutrition, abduction and disease."
"We urgently need your help to bring them relief, stability and hope."