M23 rebels in the Democratic Republic of Congo have declared a unilateral ceasefire ahead of a second round of peace talks with the government.
The rebels told a news conference in the Ugandan capital Kampala that they hoped the government would follow suit.
An attempt last month to negotiate an end to the nine-month rebellion in the east of the country failed.
Up to 800,000 people have been displaced since the rebels took up arms against the Kinshasa government in May.
"We've been for peace... today we're declaring that we're in a ceasefire," M23 spokesman Francois Rucogoza told the news conference in Kampala.
"Even if the government refuses to sign a ceasefire agreement we'll continue with the negotiations," he added.
M23 has accused the government of President Joseph Kabila of failing to honour an earlier peace deal to integrate rebels into the army.
The rebels made rapid gains late last year. They seized the main city in the region, Goma, in November, but withdrew under international pressure.
Government spokesman Lambert Mende said the government did not have much confidence in the rebel ceasefire, Reuters news agency reports.
"We don't think we can see this as a concession from people who don't tend to do what they say. We'll wait and see. We want to know why [they've made the announcement]," he is quoted as saying.
M23 say they want to improve living conditions for the people of eastern DR Congo, but the UN say they are supported by Rwanda, which has been heavily involved in its eastern neighbour since those responsible for the country's genocide fled there en masse in 1994.
The group was founded by Bosco Ntaganda, was an officer in the Rwandan army before he left to join a rebel movement in DR Congo.
He is wanted by the International Criminal Court. Prosecutors accuse him of using child soldiers and the UN says he controls several mines in the east of the country.
The government in Kinshasa has had little control over the east since the overthrow of Mobutu Sese Seko in 1997.
The region's mineral riches have been plundered by numerous groups and countries over the past 15 years and little has been spent on DR Congo's infrastructure.
President Kabila easily won re-election in 2011 in a vote described by international observers as "lacking credibility".
But he scored poorly in the east of the country and the M23 rebels refuse to accept the legitimacy of his re-election.