A US aircraft carrier arrived in South Korea on Saturday for a joint military drills aimed to better counter North Korean threats, Seoul’s navy said.

The announcement came a day after South Korea summoned the Russian ambassador to Seoul to protest a defence deal signed by President Vladimir Putin and North Korea’s Kim Jong Un in Pyongyang this week, which included a pledge to come to each other’s aid if attacked.

“The US Navy’s aircraft carrier Theodore Roosevelt… arrived at the Busan Naval Base on the morning of June 22,” the South Korean Navy said in a statement.

Its arrival “demonstrates the strong combined defence posture of the South Korea-US alliance and their firm resolve to respond to the escalating threats from North Korea,” it added.

The carrier’s visit comes around seven months after another US aircraft carrier, the USS Carl Vinson, came to the South in a show of strength against Pyongyang.