UNITED NATIONS — The results of Ibrahim Gambari’s latest attempt to engage the Burmese military leadership in diplomacy “sorely disappointed” the White House and pro-democracy activists, and some say the U.N. envoy to Burma instead may have given ammunition to Security Council members opposed to punitive measures against the junta.

Mr. Gambari, who completed a five-day trip to the country yesterday, read out a statement “on behalf” of Burma’s jailed leader, Aung San Suu Kyi. Repeating an offer she has made frequently in the past to conduct “meaningful” dialogue with junta leaders, the statement added a sense of urgency, calling for “time-bound” negotiations. However, it contained no demand to release political prisoners arrested during last month’s street demonstrations, and it did not mention several other contentious issues.

Ms. Suu Kyi has been held in prison or under house arrest since her 1990 national election victory as leader of the National League for Democracy. She has been unable to speak publicly since the time of her imprisonment, and Mr. Gambari is the only outsider to meet her in recent years. The Security Council is yet to call for Ms. Suu Kyi to address its members directly, via satellite or Internet conference, as some pro-democracy groups have demanded. Although Mr. Gambari presented the statement he read in Singapore as a sign of progress, others said his mission, in which he had failed to secure a meeting with the top junta leader, General Than Shwe, was an affront to the Security Council.

America “is sorely disappointed that Than Shwe wouldn’t meet with Mr. Gambari,” the National Security Council’s spokesman, Gordon Johndroe, told reporters in Washington. “This contradicts junta statements that they want to work with the U.N. We also urge the junta to hear Aung San Suu Kyi and to meet with her as she has asked, in order to engage in a constructive dialogue.”

The American ambassador to the United Nations, Zalmay Khalilzad, intends to meet today with representatives of groups promoting democracy in Burma, in an attempt to engage them prior to a briefing by Mr. Gambari, expected at the Security Council next week. “All the points that the council raised” before Mr. Gambari left for his latest incursion were “rejected by the regime,” the co-founder of the Washington-based U.S. Campaign for Burma, Jeremy Woodrum, said. “Gambari was rebuffed on all his requests. What we have now is the promise of talks about more talks.”

Under increased international attention to the repression in the country, the regime had appointed on October 8 one of its generals, Aung Kyi, to negotiate with Ms. Suu Kyi. But the statement Mr. Gambari read yesterday on Ms. Suu Kyi’s behalf indicated that serious negotiations are yet to take place.

The October 25 meeting she had conducted with Mr. Kyi was “constructive,” the Gambari statement on Ms. Suu Kyi’s behalf said, adding that she looked forward to “further regular discussions.” But this was not to become an open-ended process, the statement indicated. “I expect that this phase of preliminary consultations will conclude soon so that a meaningful and time-bound dialogue” with the junta leaders “can start as early as possible.”

A senior Western diplomat who spoke to reporters recently on condition of anonymity said that unless the junta obeys the council’s demands, Europe and America would launch a council drive to impose sanctions on the regime. Separately, Mr. Khalilzad warned the junta in an October 11 remarks to the council that “in two weeks, we will be back” to press for democracy. But several council diplomats said yesterday that some conciliatory sentences in Mr. Gambari’s statement on behalf of Ms. Suu Kyi would “suffice” for China to avert any attempt to impose sanctions.