ANKARA

A nuclear-powered US aircraft carrier anchored in South Korea on Saturday amid heightened tensions in the wake of a new security treaty between North Korea and Russia.

The USS Theodore Roosevelt entered the naval base in Busan, 320 kilometers (198.83 miles) southeast of the capital Seoul, early Saturday, joined by the Aegis-equipped destroyer USS Halsey and the USS Daniel Inouye, Seoul-based Yonhap News reported, citing the South Korean Navy.

It marked the first arrival of a US aircraft carrier in South Korea in seven months, since the November visit of the USS Carl Vinson.

Saturday's arrival came as the three countries are expected to hold their first-ever trilateral multidomain exercise, called Freedom Edge, later this month amid joint efforts to bolster security cooperation against North Korean threats.

The three allies decided to launch the exercise during three-way talks held on the sidelines of the Shangri-La Dialogue security conference earlier this month in Singapore.

On Wednesday, North Korea and Russia inked a new partnership agreement after a summit in Pyongyang between the two countries' leaders, vowing to provide each other military assistance "without delay" if either is attacked by a third country.