Two more British warships will join a Royal Navy frigate in Japan by the end of the year to help enforce sanctions on North Korea, while plans are underway for British ground troops to conduct an exercise with their Japanese counterparts to assist in an international effort to enforce sanctions on Pyongyang, a senior British foreign ministry official said Friday.

Speaking to reporters in Osaka, Mark Field, who serves as minister of state for Asia and the Pacific at the Foreign Office, also said that a U.K.-Japan economic partnership agreement would not be difficult to achieve, with terms likely to be similar to the one Japan concluded with the European Union in December.

The Royal Navy frigate HMS Sutherland is in Yokosuka, Kanagawa Prefecture, to help monitor North Korean trade at sea. Two other ships, the HMS Albion, an amphibious transport that can carry hundreds of marines, and the HMS Argyll are also scheduled to come to Japan.