UNITED NATIONS — In a dramatic letter, the leaders of Burma’s pro-democracy movement yesterday pleaded with Secretary-General Ban and the U.N. Security Council to intervene on their behalf.

But though he called recent actions by the country’s military rulers “abhorrent and unacceptable,” Mr. Ban appeared to endorse a plan advanced by the junta, which the opposition leaders, who are in hiding, declared unacceptable.

In Burma, the junta announced that despite the demonstrations and the worst unrest in the country since the 1988 coup that led to the imposition of military rule, they did not plan to change course.

Japan announced it would cut $4 million in aid to the country.

“As you know, we are on the run and may be arrested any day,” the leaders of a group known as the 88 Generation Students wrote. They called on China and Russia to withdraw their threat to veto any meaningful Security Council action, and they asked Mr. Ban to call the leader of the junta, General Than Shwe, and ask him to release political prisoners.

“This may be the last letter we send to you before our own arrest and torture and we send it with utmost urgency,” the three leaders of the movement who have not yet been captured, Tun Myint Aung, Nilar Thein, and Soe Htun, told Mr. Ban, adding that they remain committed to a peaceful transition to democracy.

“I have not yet received any letter concerning that,” Mr. Ban told The New York Sun yesterday afternoon. He said he has been communicating closely with General Shwe and that he planned to discuss the situation in Burma first with leaders of neighboring countries and later with Burma’s leaders. Calling the treatment of demonstrators in Burma “abhorrent and unacceptable,” Mr. Ban said the generals “should think about the future of their country and of their people, reflecting and respecting all the wishes of the international community.”

Mr. Ban added, however, that he would “strongly urge to Myanmar authorities to implement fully the seven-point road map for democratization.” The plan, which ultimately calls for a general election, has come under heavy criticism from the opposition leaders, who say it excludes several ethnic groups and important political forces in Burma. Until now, the United Nations has refrained from explicitly endorsing it.

The road map includes the enactment of a proposed new constitution, which, critics say, is meant to enshrine the hold of the generals over Burma. In Burma’s last election in the 1980s, the pro-democracy leader Aung San Suu Kyi was elected by a large majority, but in 1988 the generals suspended the constitution and placed Ms. Suu Kyi under arrest. She has been held in jail or under house arrest since then.

The letter by the 88 Generation leaders was transferred out of Burma to the Washington-based director of the U.S. Campaign for Burma, Aung Din, who sent it yesterday to Mr. Ban and to ambassadors of the five permanent members of the Security Council, Mr. Din told the Sun yesterday.

In it, the leaders refer to an October 12 non-binding Security Council statement that called on the junta to release all political prisoners. The generals, according to the letter, responded to the council’s statement by claiming it “is not in line with the desire of entire people of the country.” Instead, the junta vowed to “continue its seven-step road map.” The next day, the letter says, three leaders of the 88 Generation movement, Htay Kywe, Aung Thu, and Thin Thin Aye, aka Mie Mie, were arrested. “Many activists are also arrested throughout the country and thousands of students, civil servants, and civilians are forced to attend the mass rallies, organized by the regime to support the national convention and denounce the protesters,” the opposition leaders said in the letter.

“Thousands of protesters, including monks and students, continue to suffer ill-treatment and severe torture in detention centers, and some passed away in custody,” they said. “Many monks in detention are forcibly disrobed and sent to prison labor camps. The military regime is continuously creating a climate of fear and the people of Burma are continuously being traumatized and brutalized.”

The council’s statement, the writers said, “is not enough, and more decisive measures are needed immediately.” They called on the council to pass a binding resolution calling for the release of all prisoners, including Ms. Suu Kyi, and to “engage in a meaningful political dialogue” with her party, the National League for Democracy, as well as with “ethnic representatives for genuine national reconciliation and democratization” — as opposed to the seven-point road map.

“We expressed our support for the seven-point road map,” the Vietnamese ambassador to the United Nations, Le Loung Minh, told the Sun. Besides being a neighbor of Burma, Vietnam was elected yesterday, along with four other countries, including Libya, as non-permanent members of the Security Council.