U.S. President Joe Biden sent a letter to President Moon Jae-in expressing gratitude that South Korea joined financial sanctions and export controls against Russia in response to its invasion of Ukraine.

According to Moon's spokesperson Park Kyung-mee, in the letter sent Monday, Biden said South Korea's stern measures will convey a strong message in support of Ukraine's sovereignty.

The U.S. leader also praised Seoul's decision to release strategic oil reserves, stating that the move demonstrates the power of countries working to stabilize the global energy market and achieve a joint goal in energy security.

Biden said Korea's leadership will continue to be important in defending a rules-based international order.