SEOUL - South Korea will join a multinational drill aimed at deterring the spread of weapons of mass destruction, the defense ministry said Tuesday.

South Korea will join the United States, Japan and Australia for the Proliferation Security Initiative (PSI) drill, a US-led effort launched in 2003, on Sept 27 in waters some 100 kilometers off the southern port city of Busan.

Seven warships and 11 aircraft will be mobilized for the one- day drill, hosted for the second time by South Korea, according to the ministry.

South Korea endorsed the PSI in 2009.