North Korean Foreign Minister Choe Son-hui (center) shakes hands with Russian Ambassador to North Korea Alexander Matsegora before leaving for Moscow on Monday, in this photo provided by the North's official Korean Central News Agency the next day. (Yonhap)

North Korean Foreign Minister Choe Son-hui has departed for Russia for an official visit, the North's state media reported Tuesday, in a visit that comes as the United States said the North sent about 10,000 soldiers to train in eastern Russia.

The visit by Choe to Russia is expected to include discussions about a potential visit by North Korean leader Kim Jong-un to Moscow amid deepening military ties between the two countries.

Choe left Pyongyang International Airport on Monday, the Korean Central News Agency said in a short dispatch. Vice Foreign Minister Kim Jong-gyu and Russian Ambassador to North Korea Alexander Matsegora were present to see Choe off.

The report came as the chief of the North Atlantic Treaty Organization confirmed Monday that North Korean troops have been deployed to Russia's western front-line Kursk region. The move is seen as intended to support Russia's forces in the near future.

The Russian Embassy in North Korea said that Choe's visit is part of a "strategic dialogue" agreed upon by the leaders of both countries.

"In accordance with the spirit and terms of the new treaty, both sides will regularly engage in in-depth consultations on bilateral relations and international politics at the highest diplomatic level as well as at levels between deputy foreign ministers and heads of structural departments," the embassy posted on its Facebook account.

There is widespread speculation that Choe's visit may involve talks with Russian officials to arrange a potential visit by Kim to Moscow for talks with Russian President Vladimir Putin.

The agenda could also involve a joint response strategy to address the international community's criticism of North Korea's deployment of soldiers to Russia's front lines in its war with Ukraine.

"It is anticipated that both sides will discuss a joint response strategy for after the U.S. presidential election, along with planning the schedule for Kim's visit to Russia," said Hyun Seung-soo, deputy director of the Korea Institute for National Unification, adding that Kim's visit to Moscow could happen as early as next year.

North Korea and Russia have been bolstering military and other cooperation, with Kim and Putin holding summit talks in June in Pyongyang. They signed a new partnership treaty that includes a mutual defense clause.

The North Korean foreign minister last visited Russia in September. She also traveled to Moscow in January, where she met with Putin. (Yonhap)