KUWAIT ASKS TO USE FOREIGN FLAG TANKERS, U.S SAYS Kuwait has asked at least four countries, including the United States, Soviet Union, Britain and China, for temporary use of their flags or tankers to protect Kuwaiti oil shipments in the troubled Persian Gulf, Reagan Administration officials said. The officials confirmed a New York Times report that Kuwait wants to transfer some of its oil tankers to U.S. or Soviet registration in hopes Iran would be reluctant to launch new "Silkworm" missiles at superpower flags. The United States has vowed to keep the gulf open to international oil traffic and has warned Tehran against using the Chinese-made missiles recently installed in Iran near the mouth of the gulf. "They (the Kuwaitis) have also asked Britain, China and possibly some other European countries to lease tankers to carry their oil," one of the administration officials, who asked not to be identified, told Reuters. The United States is considering the request to temporarily transfer Kuwaiti ships to American registration, but such a move could create insurance and other problems, the officials said. U.S. defense officials told Reuters yesterday that Kuwait had decided for at least the time being not to accept a U.S. offer to use American warships to escort its tankers in the gulf, where both Iran and Iraq have been attacking shipping.