BANGKOK, Thailand - Signs of clandestine military cooperation between North Korea and Myanmar are feeding "growing concerns" about Asian security, U.S. Secretary of State Hillary Rodham Clinton said in Thailand yesterday.

"It would be destabilizing for the region; it would pose a direct threat to Burma's neighbors," Clinton told reporters in Bangkok after meeting Thai Prime Minister Abhisit Vejjajiva. She used Myanmar's former name.

Clinton did not comment specifically on allegations that North Korea might be helping Myanmar's military government set up uranium or other nuclear facilities.

The United States and its Asian allies are on alert for suspected proliferation of conventional or nuclear materials by North Korea.

The U.S. Navy recently followed the Kang Nam I, a North Korean freighter that was headed in the direction of Myanmar with unknown cargo. The ship turned around and returned home earlier this month.

The U.N. Security Council voted unanimously in June to adopt a U.S.-backed resolution to punish North Korea for detonating a nuclear device May 25.

The measure seeks to curb loans and money transfers to North Korea and steps up inspection of cargoes suspected of containing material that might contribute to the development of nuclear weapons or ballistic missiles.

Some proliferation experts and Myanmar dissidents said the country's secretive military regime was trying to develop nuclear weapons, a suspicion that has gained currency with the release last month of 800 photographs of purported tunnels in the country built with North Korean aid.

A South Korean intelligence official quoted by the Associated Press said satellite imagery of the Kang Nam suggested it carried nuclear cargo. U.S. officials suggested the shipment might have been artillery or small arms.

Clinton called reports that the United States might be willing to offer North Korea a package of incentives to encourage its leaders to return to stalled talks about dismantling its own nuclear-weapons program a "misinterpretation."

"The United States stands ready to work with North Korea if and only if and when they are ready to resume" talks about complete denuclearization, she said.

Before diplomacy with it foundered last year, impoverished North Korea was receiving international aid in exchange for dismantling a plutonium-producing facility.

Clinton was to head today to the resort island of Phuket to discuss Myanmar, North Korea, and other security issues with counterparts in the Association of Southeast Asian Nations and the 27-member Asean Regional Forum, which includes China, Russia, and India.

She called on Myanmar to release Nobel Prize-winning opposition leader Aung San Suu Kyi and other political prisoners. Clinton also expressed deep concern over alleged human-rights abuses, including rapes.

She said she expected "fair treatment" for Suu Kyi, who is on trial and could face as many as five years in prison on charges of violating the terms of her house arrest.

She has spent a total of 13 years in detention since her party won 1990 elections, a vote not honored by the army.

Asean foreign ministers, meeting in Phuket this week, condemned North Korea's nuclear test and urged the country to return to the six-party talks that involve both Koreas, Japan, the United States, Russia, and China.

The group, of which Myanmar is a member, also called for the release of Suu Kyi.

But in Phuket, Abhisit, the Thai prime minister, said yesterday that Asean "cannot interfere" in Suu Kyi's trial.

"Clearly, the Myanmar government insists that the matter is now within the hands of the courts, and we'll have to await the outcome of the trial and look at the legal possibilities," Abhisit told reporters.