"Yesterday our delegation led by Bo Mya (commander of the KNU's military wing) met with Khin Nyunt in Rangoon," Phado Mahn Sha, the group's secretary general, told AFP by telephone on Saturday from western Thailand near the Myanmar border.
The talks in the capital are aimed at formalising a ceasefire hammered out by the two sides in December as a means of ending half a century of military struggle.
Mahn Sha labelled that pact a "gentleman's agreement" and said the KNU was seeking to seal a formal ceasefire "in the next few days," although it was too early to claim success.
The delegation was due to meet with the ruling State Peace and Development Council (SPDC) again on Saturday but it was not clear who would represent the junta, he added.
A shroud of secrecy has been draped over the proceedings in
Yangon, where the KNU's 20-member delegation has been sequestered in a military guest house since arriving on Thursday for a fourth round of talks with the SPDC.
State media did not report on the Khin Nyunt meeting. General Khin Nyunt, the government's prime architect of a plan to hold a national convention this year aimed at drafting a new constitution with the help of ethnic groups, has received nine minority groups out of the 17 who have signed ceasefire agreements with the junta.
The KNU are said to be seeking the ceasefire before considering participating in the national convention, the first step in Khin Nyunt's seven-point "road map" for democracy announced last August.
General Khin Nyut (2nd R) is
pursuing peace with the Karen
But Mahn Sha expressed concern that despite the ongoing peace talks the two sides are still fighting.
"Now the fighting has not stopped, because the SPDC did not stop its front lines," he said, describing how a number of skirmishes in recent days have led to casualties on both sides.
Thousands of Karen refugees who have fled fighting from their
home state are living in camps along Thailand's northwestern border with Myanmar. Most Karen are Anglican, while Bo Mya is a devout Seventh-Day Adventist.
The KNU is one of the few remaining rebel groups still fighting
against Yangon rule. The junta estimates there are 7000 rebels in the insurgent group.