The US and South Korea are set to begin a two-day joint naval exercise in the Sea of Japan, according to reports.
Citing an anonymous South Korean source, Yonhap News Agency reported that the exercise is aimed at enhancing the detection capabilities of intrusions into South Korean territorial waters.
It will reportedly involve two US destroyers, a South Korean destroyer and a submarine and two helicopters. However, South Korean Navy officials have not yet confirmed this.
North Korea had asked the US to drop plans to conduct military exercises on the Korean Peninsula and the surrounding area.
Reports emerged that this was rejected by the US, claiming 'it was a hidden threat'.
The US and South Korean navies participated in the annual Clear Horizon exercise off the south of the Korean Peninsula in October 2014.
The five-day event involved vessels and expeditionary units, which practised clearing routes for shipping and executed training surveys for clearing operational regions.
Clear Horizon, which is one of 20 annual bilateral training exercises executed every year between both navies, is aimed at strengthening the coalition and maintaining stability and peace around the peninsula and across North East Asia.