Russian Foreign Minister Sergey Lavrov is set to visit North Korea this weekend, in a sign of deepening relations between Moscow and Pyongyang as North Korea gets pulled deeper into Russia’s war in Ukraine.

Lavrov “will make a visit to the Democratic People’s Republic of Korea on July 11-13 for the talks that will be held as part of the second round of strategic dialogue between the top diplomats,” foreign ministry spokesperson Maria Zakharova said, according to Russian state media agency TASS.

North Korea’s state news agency, KCNA, also reported Wednesday that Lavrov would be visiting “at the invitation of” Pyongyang’s foreign ministry.

Lavrov’s trip comes at a crucial time for Russian-North Korean relations, with Pyongyang set to deploy an additional 25,000 to 30,000 soldiers to assist Moscow’s scaled-up assault on Ukraine, according to Ukrainian intelligence – adding to the estimated 11,000 soldiers Pyongyang sent last year.

It also comes as the US has grown increasingly frustrated with Russia. US President Donald Trump has accused his counterpart Vladimir Putin of throwing “bullsh*t” at peace talks, and pledged more support for Ukraine.