The United States and Japan have signed an agreement for Japan to purchase and manufacture under license up to six EP-3 electronic surveillance aircraft to strengthen its intelligence gathering capabilities, the U.S. Embassy said Wednesday.

An embassy spokesman said Foreign Minister Sosuke Uno and U.S. Ambassador Mike Mansfield exchanged diplomatic documents on the agreement Tuesday.Under the arrangement, a group of Japanese ordnance manufacturers will produce the American-designed EP-3 flying electronic eavesdropper under license from the United States.

The main task of the EP-3 aircraft will be to locate and monitor increased activities of Soviet warships and military aircraft in the Pacific and to collect and analyze what military experts call "radar signatures" or wave lengths and other characteristics of electronic and communications gear, The Japan Times reported.

The aircraft also will be used to evaluate the electronic warfare capability of MSDF warships during exercises, defense agency officials told the newspaper.