Russia’s foreign ministry summoned Lee Do-hoon, the South Korean ambassador to Moscow, on April 5 to protest Seoul’s unilateral sanctions against Russian entities and individuals. The sanctions, announced on April 2, target Russian vessels, institutions and individuals for violating U.N. Security Council resolutions by providing military and financial assistance to North Korea.

As tensions between Moscow and Seoul escalate, South Korea faces mounting pressure to provide military assistance to Ukraine — a move that could be announced after the country’s general elections on April 10.