BANGKOK: Thai authorities were acting on a tip from the United States when they seized tons of illicit weapons from a plane from North Korea, a senior official said Thursday.

The Ilyushin Il-76 transport plane was impounded Saturday in Bangkok during what officials said was a scheduled refueling stop. Thai authorities found a reported 35 tons of weaponry aboard it, all exported from North Korea in defiance of U.N. sanctions.

Speaking at a news conference, National Security Council chief Thawil Pliensri confirmed media reports that there had been U.S. assistance in the seizure, but gave no details.

He said that Thailand was waiting for advice from the United Nations on whether the weapons should be destroyed.

The U.N. sanctions — which ban North Korea from exporting any arms — were imposed in June after the reclusive communist regime conducted a nuclear test and test-fired missiles. They are aimed at derailing North Korea's nuclear weapons program, but also ban it from selling any conventional arms.

Thawil revealed little else new at his news conference, which seemed aimed at quashing some rumors. He denied that Thailand would receive a reward or bounty for the seizure, or that it was pressured to act, saying it took action "as a member of the world community."

He added, however, that Thailand would like to be compensated if possible by the U.N. for the cost of transporting the weapons, which were taken to an Air Force base in the nearby province of Nakhon Sawan.

It is still not known where the weapons — said to include explosives, rocket-propelled grenades, components for surface-to-air missiles and other armaments — were to be delivered. The plane's papers, which described its cargo as oil-drilling machinery, said the shipment was to be delivered to Sri Lanka.

Arms trade experts have speculated that the cargo may have been destined for conflict zones in Africa, Iran or Myanmar.

U.S. Treasury Department records show that the plane had previously been registered with firms controlled by suspected arms trafficker Russian Viktor Bout, who is currently being held in Thailand. The U.S. is trying to extradite him on terrorism charges. On Wednesday, he denied any involvement with the plane, according to Russian news agency ITAR-Tass, accusing the media of trying to influence the decision in his extradition hearing.