A U.N. special envoy to Myanmar said Sunday he told its military government that it must address concerns about recent elections, which critics charge were rigged.

Vijay Nambiar, who is also chief of staff for U.N. Secretary-General Ban Ki-moon, spoke Sunday to reporters as he was ending a two-day visit.

He said he listened to as many parties as possible about their "hopes, expectations and concerns at this critical juncture" following the Nov. 7 polls and the release of opposition leader Aung San Suu Kyi from house arrest.

He said concerns about the elections have to be addressed "as transparently as possible."

"This is important for laying the foundation of a credible transition" to democratic rule, he said.

Nambiar said he also called for the release of political prisoners, estimated by human rights groups to number more than 2,200.

Nambiar met Saturday with Nobel Peace Prize laureate Suu Kyi, who said the talks were "very valuable" but that they might need "many and frequent meetings to sort out all the problems we are facing."

Since her release Nov. 13 from more than seven years of continuous house arrest, Suu Kyi has been busy talking with diplomats, politicians and international agencies.

The military has ruled Myanmar since 1962 and the Nov. 7 elections were widely criticized as being unfair, with vote-rigging to favor the military-backed Union Solidarity and Development Party. Still incomplete results give the party a sweeping majority in both houses of parliament.

The official Union Election Commission has repeatedly corrected announced results that showed turnout exceeding 100 percent in some constituencies and declared two pro-junta candidates winners in constituencies in Kachin State where voting had been canceled.

The results ensure the military retains power behind the scenes as well as overtly in parliament, which will become a powerful body. The president, who does not need to be an elected lawmaker, will appoint Cabinet ministers and can call the military to take over in case of a national emergency.

The previously elections in 1990 were overwhelmingly won by the Suu Kyi's National League for Democracy party, but the military did not recognize the results.

Nambiar, who also met with Foreign Minister Nyan Win, election commissioners and representatives of some ethnic political parties, said the U.N.'s role in promoting political reconciliation was appreciated by all sides.

"The United Nations looks forward to continuing this dialogue through direct engagement with all parties to help advance national reconciliation and the establishment of a democratic and civilian government in a way that contributes to Myanmar's stability and development," he said.

It was Nambiar's first visit to Myanmar since he took over the position of special envoy from Ibrahim Gambari, who last traveled to Myanmar in June 2009.

A long line of U.N. officials, including Ban, has attempted to broker talks between the opposing sides, but have failed to bring them together despite numerous claims of breakthroughs.