US envoy says unilateral action possible against North Korea

Tokyo: The United States may take unilateral action against North Korea, a U.S. special envoy for the isolated state said on Sunday, two days after it carried out its fifth and biggest nuclear test, in defiance of U.N. sanctions.

"In addition to action in the Security Council, both the U.S. and Japan, together with the Republic of Korea, will be looking at unilateral measures, as well as bilateral measures, as well as possible trilateral cooperation," said Sung Kim, the envoy.

Speaking to reporters in Tokyo after meeting senior Japanese foreign ministry officials, Kim described North Korea`s behaviour as "provocative and unacceptable".