A North Korean ship suspected of transporting missiles or other weapons technology was intercepted by the U.S. Navy two weeks ago and turned back, U.S. officials said Monday.

The incident in the South China Sea was the Obama administration’s highest-profile confrontation in the past year with North Korea and with Burma, the suspected destination of the weapons.

For years, the United States and other countries have been locked in a battle to prevent North Korea from exporting weapons technology, including nuclear capabilities. U.S. officials said they think there were weapons on board the ship two weeks ago that violated a U.N. embargo. The New York Times first reported about the incident.

The ship was identified as the M/V Light — a North Korean merchant cargo ship. On May 26, the Navy sent the destroyer USS McCampbell to catch up with the vessel, said Marine Col. David Lapan, a Pentagon spokesman.

The U.S. destroyer hailed the North Korean vessel four times to try to board it but was rebuffed by the ship’s master, a State Department official said. The destroyer continued to track the vessel for three days.

Meanwhile, U.S. officials reached out to North Korean officials through diplomatic channels, one U.S. official said. Because the two countries do not have diplomatic relations, they usually talk through North Korea’s delegation to the United Nations.

The United States also contacted other Southeast Asian countries, which agreed that the North Korean ship needed to be inspected, top White House nuclear adviser Gary Samore told U.S. and South Korean reporters Monday.

After three days of diplomatic pressure, the vessel turned around, a sign that U.S. officials said confirmed their suspicions that illegal weapons were on board. Representatives at North Korea’s U.N. office said they had no knowledge of the incident, and the North Korean state news agency did not carry any reports of the confrontation.

The United States had begun tracking the M/V Light shortly after it left a North Korean port, according to a U.S. military official, who spoke on the condition of anonymity because details of the operation remain classified. But because the ship was officially registered in Belize, U.S. officials said, they first obtained permission from the Central American country before intercepting it.

The Navy, however, stopped short of forcibly boarding the ship to avoid sparking an escalation in tensions on the Korean Peninsula, officials said.

In recent years, the United States and other countries have intercepted ships and planes suspected of being used by North Korea to export weapons and nuclear capabilities in exchange for food, money and materials needed for continued arms development.

Although some officials said the M/V Light was thought to be headed to Burma, they avoided singling out the country in official statements. The United States and other nations have accused the military-dominated government in Burma, also known as Myanmar, of widespread and systematic human rights violations.

The most recent standoff echoed a 2009 incident in which the United States sent a Navy destroyer to turn back a North Korean ship thought to be carrying weapons to Burma.

For years, U.S. officials have watched the relationship between Burma and North Korea warily, suspecting cash-strapped North Korea of illegally selling weapons and even nuclear technology to the developing Southeast Asian nation. U.S. diplomatic cables released by WikiLeaks in December described suspicions of clandestine cooperation between the two isolated countries and indications that hundreds of North Koreans were at one point working at a covert military site in the Burmese jungle.

Burmese officials have denied nuclear ambitions, and they told Sen. John McCain (R-Ariz.) during his visit this month that their country was too poor to pursue a nuclear arms program.

Some members of Congress have called for a formal report by the Obama administration on North Korean-Burmese weapons collaboration. A bill demanding such a report is pending before the Senate Foreign Relations Committee.

“Of late, the administration’s tactic with Burma has been to try to reach out and to exercise strategic patience,” said Michael Green, a senior adviser at the Center for Strategic and International Studies, a Washington-based think tank. “But while this incident was a clear success as far as a demonstration of seriousness with North Korea, it raised some real questions about whether we need to revisit our Burma policy and what we have to show for that patience.”