BANGKOK, AUG. 11 -- Burmese strongman Ne Win has publicly admitted mistakes by his government for the first time in his 25-year rule, western diplomats said today.

"The entire truth should be submitted without any attempt to hide the facts," the 75-year-old leader told a meeting of senior officials and politicians in Rangoon yesterday.

The reclusive leader ordered them to stop covering up shortcomings and to review accurately failures in their work since 1974, Rangoon radio said last night.

He also hinted that changes might be made to the country's 13-year-old constitution.

Burma, potentially a rich rice, gem and timber producer, has slumped to the depths of poverty since Ne Win's 1962 coup. Political unrest provoked by food shortages in the early 1970s led to the last round of changes in the constitution.

"Only when we have the facts in hand can we make sure that future work plans . . . contain fewer mistakes: We of course cannot avoid mistakes completely," the radio, monitored in Bangkok, reported him as telling the meeting held in parliament.

Western diplomats in Bangkok described the meeting of Burma's secretive leadership as unusual. "Ne Win never admits anything is wrong," commented one envoy.