Photo/IllutrationThe North Korean tanker Chon Ma San and the Maldives-registered tanker Xin Yuan No. 18 line up at night for a suspected direct transfer of cargo on Feb. 24. (Provided by the Defense Ministry)

Japan and the United States are putting together a multilateral strategy that would involve key allies to crack down on North Korea's disregard for U.N. sanctions in Asia-Pacific waters.

The crux of the plan calls for setting up a maritime network to expand interceptions of vessels flouting measures backed by the international community to protest North Korea's nuclear and missile programs.

Japan and the United States are trying to arrange a high-level meeting involving nations in Asia and Europe to discuss ways to close off loopholes that Pyongyang is exploiting to bring in petroleum and other products, often through direct transfers at sea, according to several government sources.

Prime Minister Shinzo Abe called his British counterpart, Theresa May, on Feb. 26 and raised the issue of ship-to-ship transfers being used by North Korea to get around U.N. sanctions.

In addition to the United States and Britain, South Korea, Australia and Singapore are expected to be invited to the international conference at a still undecided location, the sources said.

Overtures will also be made to France as it has territories and military bases in the South Pacific and the Indian Ocean.

In explaining the need for greater international cooperation, a high-ranking Foreign Ministry official said, "The area for surveillance of the open seas is vast and we do not have a sufficient number of ships to do the job."

One idea being considered is to set up separate surveillance areas for each nation as well as establish periods for the maritime surveillance.

At a Feb. 27 news conference, Foreign Minister Taro Kono said there was a need for "greater cooperation with a larger number of nations" because North Korea is becoming ever more crafty in getting around U.N. sanctions.

The Maritime Self-Defense Force and Japan Coast Guard will continue with surveillance duties against North Korean smuggling in the Sea of Japan and East China Sea.

Foreign Ministry officials announced Feb. 27 that they had reported another highly suspicious incident to the U.N. Security Council involving a ship-to-ship transfer by a North Korean vessel.

The suspected transfer occurred in waters about 220 kilometers east of Shanghai on the night of Feb. 24 between a North Korean-registered ship and a tanker registered in Maldives.

To provide further cooperation with Japan, the U.S. Coast Guard is also considering dispatching cutters to the Asia-Pacific region.