North Korean Foreign Minister Pak Ui-chun arrived in Moscow on Sunday as part of a four-day visit to discuss concerns in the Northeast Asian region.

During Pak’s meeting with Russian Foreign Minister Sergei Lavrov on Monday, the two are expected to discuss North Korea’s revelation of its uranium enrichment program and its artillery attack on South Korea’s Yeonpyeong Island. Both moves have heightened tensions on the Korean Peninsula.

The two foreign ministers are also expected to discuss economic cooperation between North Korea and Russia.