Cambodian Prime Minister Hun Sen's visit to Myanmar seeking to revive peace efforts after last year's military coup has provoked an angry backlash among critics, who say he is legitimising the army's seizure of power.
Hun Sen is the first head of government to visit Myanmar since the military seized power last February.
The authoritarian Cambodian leader has held power for 36 years and keeps a tight leash on political activity at home.
In his role as the current chairman of the Association of Southeast Asian Nations, he met with Senior General Min Aung Hlaing, who ousted the elected government of Aung San Suu Kyi, plunging Myanmar into violent conflict and economic disaster.
In their meeting, Min Aung Hlaing told Hun Sen Myanmar had extended to the end of the year a ceasefire with all ethnic armed organisations (EAOs) that was originally set to expire at the end of February, according to a joint statement released late on Friday by the two leaders.
Last April, ASEAN leaders, including Min Aung Hlaing, agreed on a five-point roadmap toward a peaceful settlement of the Myanmar crisis, including an end to violence and a political dialogue between all stakeholders.
Myanmar's leader on Friday "pledged support (to the ASEAN special envoy) ... in fulfilling his mandate to implement the five-point consensus in accordance with the ASEAN charter", the statement said.
Hun Sen was accompanied by Deputy Prime Minister Prak Sokhonn, the current ASEAN special envoy, and other Cambodian officials.
Protests and rallies were held in some parts of Myanmar as people expressed anger over the visit.
Hundreds of protesters burned portraits of the Cambodian prime minister and chanted, "Torch inhumane Hun Sen. People who engage with Min Aung Hlaing should die horrible deaths", videos of one protest posted online showed.
Myanmar's military leader was in October barred from attending ASEAN meetings after the group's special envoy was prevented from meeting with Suu Kyi and other political detainees, which was one of the stipulations of the agreement.
Myanmar's military has said Hun Sen will not be allowed to meet with Suu Kyi, who was convicted in December on charges of incitement and violating coronavirus restrictions and sentenced to four years in prison - a sentence Min Aung Hlaing then cut in half.
An official familiar with Suu Kyi's legal proceedings said she appeared at a special court in Naypyitaw, Myanmar's capital, on Friday for hearings in three corruption cases against her that include allegations she diverted charitable donations to build a residence and abused her authority.
The army's takeover prevented Suu Kyi's National League for Democracy party from beginning a second term in office.
It won a landslide victory in national elections in November 2020 and independent election observers did not find any major irregularities.
The Myanmar military has recently engaged in violent suppression of all dissent, disappearances, torture and extra-judicial killings.
It has also launched air strikes and ground offensives against ethnic armed rebel groups.
Security forces have killed about 1443 civilians, according to a detailed tally by the Assistance Association for Political Prisoners.
As the crackdown has become more severe, an armed resistance has grown inside the country.
The National Unity Government, an underground Myanmar opposition group and parallel administration, urged Hun Sen to stay away.
"Meeting Min Aung Hlaing, shaking blood-stained hands. It's not going to be acceptable," said Dr Sasa, a spokesman for the group who uses one name.
Australian Associated Press