In a statement, Ibrahim Gambari said there was now "a process going which would lead to substantive dialogue between the government and Aung San Suu Kyi as a key instrument in promoting national reconciliation in an all-inclusive manner"
The statement - which said "the sooner such a dialogue can start, the better" - followed Mr Gambari's second visit to Burma since the suppression of peaceful anti-government protests in September.
His meeting with Aung San Suu Kyi came after days of talks with Burma's ruling military junta had ended without a breakthrough.
Senior Burmese officials earlier rejected Mr Gambari's offer to mediate in negotiations with the National Movement for democracy leader, according to the regime's New Light paper.
Aung San Suu Kyi is under house arrest in Yangon and the government blocks almost all access to her, with Mr Gambari's visits being rare exceptions.
A senior official said the regime could not negotiate with the 62-year-old until she dropped calls for sanctions against it.
Although the UN issued a statement saying Mr Gambari's visit had included "open and detailed discussions" with the Burmese prime minister, Thein Sein, he was not given an audience with the head of the junta, General Than Shwe.
The envoy had met Gen Shwe in October when international pressure was more intense, and his failure to meet him on this visit has been interpreted by some as a snub.
Widespread protests broke out across Burma in September. The military detained at least 3,000 people, including Buddhist monks, and opened fire on crowds.
Mr Gambari told generals that "a return to the status quo before the crisis would not be sustainable" and that his proposed meeting with opposition leaders would be in line with "international expectations".
It is thought the junta is not concerned about UN pressure because India and China, members of the security council, continue to trade with it and oppose tougher sanctions.
