SEOUL, June 11 (Reuters) - Defence ministers of South Korea and the United States on Saturday condemned North Korea's preparations for a nuclear test, saying this and a series of missile launches threaten the peace and safety of the Korean peninsula and the international community.

South Korea and the United States plan to expand the scale of joint military exercises to maintain deterrence, South Korea's defence ministry said in a statement.

Defence Minister Lee Jong-sup and U.S. Defence Secretary Lloyd Austin met on Saturday at the Shangri-La Dialogue, an Asia security gathering in Singapore.