YANGON: Myanmar's military regime took yet another step to expunge Aung San Suu Kyi from the political scene Wednesday by effectively barring her from the first elections in 20 years and pressuring her opposition party to expel her from its ranks.

A new election law announced Wednesday prohibits anyone convicted of a crime — as Suu Kyi was in August — from being a member of a political party. That makes the detained democracy leader ineligible to become a candidate in historic elections scheduled for some time later this year.

The United States and Britain expressed disappointment and regret at the junta's latest move. Analysts called it a clear slap in the face for the international community, which has repeatedly said the elections would not be legitimate if the detained Nobel Peace Prize laureate is barred from running.

The 64-year-old Suu Kyi is the head of the opposition National League for Democracy, which won a landslide victory in the last Myanmar election in 1990. The junta ignored those results and has kept Suu Kyi jailed or under house arrest for 14 of the past 20 years.

The new law, the Political Parties Registration Law, could also force Suu Kyi out of her opposition party. It instructs parties to expel members who are "not in conformity with the qualification to be members of a party."

Hours after announcing the blow to the opposition party, the junta offered a carrot. On Wednesday evening, authorities began to reopen several NLD offices in Yangon, by removing red wax that had been sealed over their locks since 2003 to restrict party activities, said party spokesman Nyan Win.

"Maybe they want to show some flexibility," said Nyan Win, noting that the move seemed tied to another provision of the election law that says existing political parties have 60 days from Monday to register. The government currently recognizes 10 parties.

The junta enacted five election-related laws Monday that set out the rules for the election, campaigning and conditions under which parties may participate. So far, it has made public two of the laws. The first stipulates that the junta will appoint the five-member Election Commission, which has final say over the poll's results.

U.S. Assistant Secretary of State Kurt Campbell said that the laws detailed so far are disappointing. Suu Kyi should be released from house arrest so she can "play an active role in the political life of the country going forward," Campbell said during a trip to Malaysia.

It already was widely assumed that Suu Kyi would be shut out of upcoming elections, which critics have denounced as a sham designed to perpetuate military rule.

A provision in the 2008 constitution, drafted under the junta's influence without input from the pro-democracy movement, effectively bars Suu Kyi from taking part in the polls because she was married to a foreigner. Her now-deceased husband was British.

In August, Suu Kyi was convicted of violating the terms of her house arrest by briefly sheltering an American who swam uninvited to her lakeside residence. She was sentenced to an extended 18 months of house arrest, which would keep her locked away during elections. Last month, the Supreme Court dismissed her latest appeal for freedom.

"They've used so many devices. It's like using a machine gun to kill a mosquito," said Sean Turnell, a Myanmar expert at Australia's Macquarie University. "So many of us suspected this wasn't about bringing any real change to Burma, but it is surprising how nakedly they're going about it."

The United States recently has modified its strict policy of isolating the junta to embark on a new policy of engagement. However, the Obama administration has said it will not lift sanctions on Myanmar unless its sees concrete progress toward democratic reform — notably freeing Suu Kyi and letting her party participate in elections.

"The Obama administration went out of its way to say let's begin with a clean slate. Burma has constantly presented him with a clenched fist," Turnell said.

Suu Kyi's National League for Democracy, called the election law unfair, politically motivated and designed to restrict activities of the party, which has already been battered by arrests and harassment.

The law also bars members of religious orders and civil servants from joining political parties.

The date of the elections has not been announced, and Suu Kyi's party has not said whether it will contest the balloting.

"We're going to need to study the election laws carefully once they've all been released," British Ambassador Andrew Heyn said. "But it's regrettable and very disappointing that the laws are not based on a dialogue with a range of political opinion."

He stressed that the release of political prisoners, freedom for all to participate in the elections, freedom to campaign and access to media are essential for the elections to be credible.