The South Korean navy is taking part in the Pacific Vanguard multinational naval exercise in waters near Guam with the navies of the U.S., Canada and Australia.
The drill runs for nine days, ending next Thursday.
Korea's navy confirmed that it had sent a 45-hundred ton Choi Young -class destroyer and a Lynx helicopter.
The drill is being held for the second time this year.
The previous exercise in May included Japan instead of Canada.