A US Navy destroyer intercepted a North Korean cargo ship in the South China Sea suspected of carrying missiles or other weapons and made it turn back, officials said Monday.

The cargo ship, the M/V Light, may have been headed to Myanmar with military contraband, Gary Samore, special assistant to President Barack Obama on weapons of mass destruction, told the South Korean Yonhap news agency.

The New York Times, which first reported the incident, said the ship was intercepted south of the Chinese city of Shanghai by a US destroyer on May 26.

The North Korean ship was registered in Belize, whose government gave the United States permission to board and inspect the ship, Samore and Pentagon officials said.

"We talked directly to the North Koreans. We talked directly to all the Southeast Asian countries including Myanmar, urging them to inspect the ship if it called into their port," Samore was quoted as saying.

"The US Navy also contacted the North Korean ship as it was sailing, to ask them where they were going and what cargo they were carrying."

The USS McCampbell, a guided-missile destroyer, then requested permission to board the M/V Light and was refused by the ship's master, who said it was a North Korean ship, Pentagon spokesman Colonel Dave Lapan told reporters.

The US destroyer continued to track the vessel which eventually headed back to North Korea on May 29 "in order to avoid inspection," Lapan said.

"We believe that those signs point to the fact that it was carrying an illicit cargo in violation of the UN Security Council resolutions," he said.

North Korea is subject to international and United Nations sanctions designed to curb its missile and nuclear programmes.

UN Resolution 1874, adopted in June 2009, one month after the North's second nuclear test, toughened a weapons embargo and authorized member states to intercept such shipments.

Another North Korean ship, the Kang Nam I, was forced to reverse course in 2009 after being suspected of trying to deliver military-related supplies to Myanmar.

The New York Times, quoting unidentified US officials, said the North Korean ship refused four requests for inspections.

But on May 29, the ship stopped dead in the water and turned back to its home port, tracked by US surveillance planes and satellites.

"Such pressure from the international community drove North Korea to withdraw the ship," Samore told Yonhap.

"This is a good example that shows that international cooperation and coordination can block the North's weapon exports."

The United States has frequently expressed worries over military ties between Myanmar and North Korea.

Last month Deputy US Assistant Secretary for East Asia and Pacific Affairs Joseph Yun expressed concern directly to Myanmar's new army-backed government.

US diplomatic memos released last year by the website WikiLeaks said Washington has suspected for years that Myanmar ran a secret nuclear program supported by Pyongyang.

A top Myanmar official told visiting US Senator John McCain this month that his country is not wealthy enough to acquire nuclear weapons.