South Korea’s presidential office on Thursday condemned an agreement reached by Russia and North Korea that vowed mutual defense assistance in the event of war and said it will reconsider its policy of limiting its support to Ukraine to non-lethal supplies.

The comments by a senior presidential official came hours after North Korea’s state media released the details of the agreement reached between its leader Kim Jong Un and Russian President Vladimir Putin during their summit on Wednesday in Pyongyang.

The North’s official Korean Central News Agency said the deal requires both countries to use all available means to provide immediate military assistance in the event of war.

The office of South Korean President Yoon Suk Yeol issued a statement condemning the agreement, calling it a threat to the South’s security and a violation of U.N. Security Council resolutions, and warned that it would have negative consequences on Seoul’s relations with Moscow.