Fighting between government troops and ethnic Chinese rebel fighters has raged in the Kokang region of northern Shan state since early February, causing tens of thousands of people to flee their homes, many into China.
Myanmar's airforce has also dropped bombs on Chinese territory, killing several civilians and infuriating Beijing which issued a stern rebuke and carried out live-fire military drills near the border as a warning.
"During four months fighting, about 80 to 90 people were killed from our side. More than 200 people were wounded. We will remain in our positions although the fighting has stopped."
Myanmar's army and government were not immediately reachable for comment on whether they would join the ceasefire in Kokang, a mountainous area which remains cloaked in martial law.
Myanmar's government is desperate to secure a binding ceasefire with myriad ethnic groups, many of whom have been fighting for decades, ahead of elections later this year.
Kokang rebels were quickly joined by a number of other ethnic insurgent groups and the conflict has threatened to undermine that peace bid.
Kokang has strong bonds with China -- local people speak a Chinese dialect and China's yuan is the common currency -- and tens of thousands of people have crossed the border to flee the fighting.
The news of the Kokang ceasefire declaration came on the same day as Myanmar's opposition leader Aung San Suu Kyi met Chinese President Xi Jinping in Beijing.
