Greek authorities seized almost 14,000 anti-chemical weapons suits from a North Korean ship possibly headed for Syria but did not disclose the find for nearly two years, diplomats said Wednesday.

The seizure was reported to the UN Security Council, which discussed the monitoring of nuclear sanctions against the isolated North, diplomats said.

The Greek operation was carried out in November 2009 but only reported to the United Nations in September, a diplomat told AFP on condition of anonymity in confirming the number of suits to protect against chemical weapons involved.

"It seems the shipment was headed for Latakia in Syria," a second diplomat said, noting that the Greek report to the council did not mention Syria.

"There is increasing concern because more and more of the violations before several sanctions committees seem to involve Syria."

Syria has already been linked to breaches of an arms embargo against Iran.

Both diplomats spoke on condition of anonymity as the report by the chairman of the North Korea sanctions committee, Portugal's UN Ambassador Jose Filipe Moraes Cabral, was given behind closed doors.

The UN Security Council ordered tough sanctions against North Korea after it staged nuclear weapons tests in 2006 and 2009.

The North pulled out of nuclear talks with China, the United States, Japan, Russia and South Korea in 2009 and efforts to kick start negotiations are struggling, with the United States and its allies saying that North Korea is not serious about disarmament.

In a comment sent on an official Twitter account, a British diplomat said it was "clear that North Korea (is) still violating" Security Council resolutions.

"Strong concerns in council about the ongoing proliferation efforts," added a German diplomat. Neither mentioned the seizure of the anti-chemical weapons suits.