US Secretary of Defense James Mattis and his counterpart, South Korean Defense Minister Song Young-moo, plan to wear combat uniforms when they deliver a joint-warning message to North Korea this week, according to Yonhap.

Mattis is a retired four-star US Marine Corps general, while Song is a former South Korean Navy admiral and chief of staff of his nation’s armed forces. The two men will meet for annual bilateral talks in Seoul later this week.

South Korea’s official news agency says Song proposed that Mattis wear a US Marine Corps combat uniform, instead of a suit, when they meet with US and South Korean troops on the peninsula as part of the joint event.

“I offered that to Secretary of Defense Mattis and he responded positively without hesitation,” the minister told reporters during a visit to the Philippines, for a regional security forum hosted by Southeast Asian countries.

Song plans to wear South Korea’s version of a navy combat uniform.

Song and Mattis had a bilateral meeting at the Philippines forum. They also held trilateral talks involving Japanese Defense Minister Itsunori Onodera on the margins of the ASEAN Defense Ministers’ Meeting (ADMM)-Plus.

Song told Yonhap that having the top defense officials of both countries don combat uniforms will send a highly symbolic and strong message to Pyongyang amid the current nuclear standoff.