"Whereas each of my previous visits produced some result that could be built upon, it is a source of disappointment that this latest visit did not yield any immediate tangible outcome," Gambari told the 15-member council.
Myanmar's military rulers rejected the envoy's proposal for a UN role in its referendum in May on a new constitution.
Gambari told the UN Security Council that his five-day visit did provide an opportunity to prod the government to engage the opposition in moving forward toward "a peaceful, prosperous, democratic Myanmar."
But during his visit, which ended on March 10, the military again refused Gambari's efforts to meet with its chairman, Senior General Than Shwe –as it did during his last visit in November.
The UN earlier said a meeting with Than Shwe was one of the main goals of Gambari's visit.
The military also turned down UN suggestions that they free political prisoners, including Suu Kyi, and accelerate a dialogue with her to foster political reconciliation.
The Nobel peace laureate has been detained for 12 of the past 18 years.
Gambari's visit was this third to Myanmar since authorities crushed pro-democracy marches in September in a crackdown that sparked worldwide outrage.
Gambari told reporters after the meeting that no date had been set for his return but he might meet officials from the Myanmar government in a third country to prepare for such a visit.
Expressing disappointment, Zalmay Khalilzad, the US Ambassador to the UN said: "The regime has not responded appropriately to Gambari's initiative."
His British counterpart, John Sawers, said Gambari's report was not encouraging, while adding that the best tool to sway the Myanmar government is to keep the issue in the international spotlight.
But Wang Guangya, the Chinese ambassador, whose country is a major trade partner and arms supplier of Myanmar, insisted Gambari's mission had achieved some progress.
"One can argue whether the glass is full or the glass is half full," he said.
"The situation (in Myanmar) now is better than last August and September."
The Myanmar government says it has drawn up a seven-step political "roadmap" to democracy and is making progress in drafting a constitution to be submitted to a referendum in May with a view to multiparty elections in 2010.