Top diplomats from South Korea and the United States discussed ways to respond to this week's summit between North Korean leader Kim Jong-un and Russian President Vladimir Putin.

According to Seoul's foreign ministry on Friday, foreign minister Cho Tae-yul held phone talks the previous night with U.S. Secretary of State Antony Blinken during a visit to New York.

The two officials strongly denounced Pyongyang and Moscow's signing of a comprehensive strategic partnership treaty to enhance their military and economic cooperation as a serious threat to the allies' security, as well as peace and stability on the Korean Peninsula and beyond.

Cho stressed that any cooperation that directly and indirectly supports the North's military reinforcement is a clear violation of UN Security Council(UNSC) resolutions.

He also explained Seoul's latest unilateral sanctions on the North and expanded export controls on Russia.

Blinken expressed support for Seoul's justified measures against the security threats, committing to sternly respond to any threat based on their firm alliance.