Updated

YANGON, Myanmar -- A top U.S. official will make a second visit to Myanmar on Sunday to pursue Washington's new policy of engagement, a diplomat said, ahead of controversial elections being prepared by the country's military regime.

The trip by Kurt Campbell, assistant secretary of state for East Asia, comes days after the formal disbanding of the main opposition party led by detained Nobel Peace Prize laureate Aung San Suu Kyi.

Suu Kyi has accused the ruling junta of trying to engineer the upcoming elections to ensure it retains its half-century-long grip on power.

Campbell, on his second visit in six months, will fly to Myanmar's administrative capital of Naypyitaw on Sunday to continue talks with senior Myanmar officials, according to the diplomat who was not authorized to speak to the press and spoke on condition of anonymity.

A government official said Campbell is scheduled to meet Prime Minister Thein Sein, Foreign Minister Nyan Win and Information Minister Kyaw San. The official spoke on condition of anonymity since he was not authorized to talk to the media.

Campbell also will meet Monday with Suu Kyi, who has spent 14 of the last 20 years in detention, said her lawyer, Nyan Win.

"I welcome the visit of Mr. Kurt Campbell but I don't really understand what he expected to achieve from the visit," said Nyan Win, who also is a spokesman for Suu Kyi's now-dissolved National League for Democracy.

Suu Kyi's party was disbanded on Friday under the country's new election law after it refused to register for Myanmar's first elections in two decades, polls the opposition says will be a sham. The National League for Democracy won Myanmar's last election in 1990 but the army never allowed it to take power.

A faction within the NLD that disagreed with the boycott said Friday they would form their own party called the National Democratic Force and participate in the elections.

A number of senior regime officials have recently shed their uniforms, with apparent intent to run for elections under a thinly disguised pro-military political party.

The Obama administration last year reversed the Bush administration's isolation of Myanmar in favor of dialogue with a country that has been ruled by the military since 1962.

Relations between Myanmar, also known as Burma, and the U.S. have been strained since its military crushed pro-democracy protests in 1988, killing hundreds, possibly thousands, of demonstrators. Washington is Myanmar's strongest critic, applying political and economic sanctions against the junta for its poor human rights record and failure to hand over power to a democratically elected government.

Washington has said it will still maintain political and economic sanctions toward the junta until talks with Myanmar's generals result in change.