United Nations envoy Ibrahim Gambari has left Burma after failing to initiate talks between the country's military rulers and the democratic opposition. 

Before departing for Singapore Tuesday, Gambari met with the military government's prime minister, General Thein Sein.

Burmese state television said Thein Sein told the U.N. envoy that the world body should lift economic sanctions and visa bans against Burma if it wants to see political stability there.

Gambari met Monday with opposition leader Aung San Suu Kyi, who remains under house arrest.  She said her National League for Democracy (NLD) requires enactment of the 1990 election result as a precondition for future talks.  The NLD won that election, but the military never handed over power.

The party also insists on the release of all political prisoners in Burma, including Aung San Suu Kyi.

During the four-day visit, Gambari held talks with the government's team headed by Brigadier-General Kyaw Hsan.   But he was not invited to the remote capital of Naypyidaw, and was denied contact with top leaders, including the head of state, Senior General Than Shwe.

A U.N. spokesman based in Burma described Monday's meeting at a government guest house in Rangoon as "very significant" and "a step forward."

But Aung San Suu Kyi said U.N. Secretary-general Ban Ki-moon should not visit Burma until its military rulers relinquish their monopoly on power.

Gambari is scheduled to meet Mr. Ban in India on Thursday.

Burma's military rulers say the majority of Burmese people approved of their so-called "Roadmap to Democracy," which they say will lead to multi-party elections in 2010.  Aung San Suu Kyi will not be allowed to run.

Some information for this report was provided by AP and AFP.