Bo Mya and the KNU delegation have now left Rangoon
The Burmese military government has confirmed that it has reached agreement with ethnic rebels from the Karen National Union (KNU) on ending hostilities.
In its first statement on peace talks in Rangoon with the KNU, the government said it had reached a "mutual understanding" with the rebels.
It said the two sides would now work together "for national unity, solidarity of the nation and peace and prosperity".
A delegation led by Bo Mya, head of the KNU's military wing, left Rangoon on Thursday after six days of talks with the military government.
In a sign of cordial relations between the two sides, the government statement also confirmed that a banquet on Tuesday, attended by Burmese Prime Minister, Khin Nyunt, had marked both the successful outcome of the talks and Bo Mya's 77th birthday.
But both sides have stopped short of saying a formal ceasefire has been signed.
On Thursday, a spokesman for the KNU told the BBC that the two sides had agreed an informal ceasefire, but that further talks were needed.
The spokesman said both sides had agreed to report infringements and any remedial actions.
"The first round of talks was very fruitful," David Taw, foreign secretary of the KNU, said on arriving from the talks in Thailand.
Mr Taw said the next round of talks was scheduled within a month.
The Karen are one of a handful of rebel groups still fighting the government. Ceasefire agreements have already been reached with 17 other armed groups since 1989.
The latest talks were aimed at formalising a ceasefire which was loosely agreed by the two sides in December, but which continuing reports of fighting suggest is not yet being observed.
Major offensives against the KNU in the mid-1990s greatly reduced their power and they have waged a low-level war from jungle hideouts strung out along the border.
Bo Mya has described a ceasefire as a possible first step towards settling broader political problems for his people.
But the KNU has so far refused to attend a national constitutional convention proposed by the government as a first step in a "road map" to democracy.
The inclusion of the ethnic groups is key to the credibility of the convention, which the junta hopes will help dampen international criticism over its failure to carry out reforms.
But many see it as a stalling tactic and as an attempt to isolate the main opposition party, Aung San Suu Kyi's National League for Democracy, which has not been invited to attend.