Myanmar election laws that bar opposition leader Aung San Suu Kyi from standing in polls this year are "disappointing and regrettable", US envoy Kurt Campbell said Wednesday.

"I think it would be fair to say what we have seen so far is disappointing and regrettable," Campbell told a press conference during a visit to Malaysia, part of a tour of Southeast Asia.

Campbell reiterated calls for the release of Suu Kyi, who has been detained for 14 of the last 20 years since the military junta annulled 1990 elections which her National League for Democracy (NLD) won in a landslide.

"We stand by our continuing statements about having her released and playing an active and full role inside the country," he said.

"We want her to play an active role in the political life of the country going forward."

The US has led calls from governments and human rights groups for the Myanmar junta to ensure the credibility of elections planned for this year by making the process fair and inclusive.

"We would like to see steps taken by the government to encourage domestic dialogue in anticipation and in advance of the elections," Campbell said.

However, newly released elections laws have lent weight to criticism that the polls will be a sham aimed at legitimising and entrenching the military's nearly five-decade grip on power.

Under one of the laws, Suu Kyi faces expulsion from her own party and is barred from standing in the polls -- for which a date has not yet been set -- an NLD spokesman said Wednesday.