Nikki Haley, US Ambassador to the United Nations, said Tuesday that Washington is concerned about possible Russian support to the North Korean regime.

The statement came amid the US attempts to urge the Chinese government to enforce UN sanctions on North Korea, a country that the Chinese government has long been allied with. Haley later gave a statement to US officials, warning them of the possibility of a de facto Russian-Korean alliance.

"I'm concerned that Russia may backfill North Korea," she told US legislators. "We just need to keep the pressure on China, we need to keep our eyes on Russia, and we need to continue to let the North Korea regime to know...

we just want them to stop the nuclear activity."

US and Russian Approaches to North Korea

Relations between the United States and the DPRK have been hostile ever since the end of the Korean War, in which US military campaigns left almost a fifth of the North Korean population dead.

Recently, tensions have been high due to repeated tests of nuclear and ballistic missiles by the North Korean government. The missile tests have drawn condemnation from both the United States and the international community. The US and DPRK now have no official diplomatic relations; Sweden acts as a diplomatic liaison between the two countries.

Although the relationship between Russia and North Korea was weakened after the fall of the Soviet Union at the end of the Cold War, it gained more ground after Kim Jong-Un visited in 2014.

Russia and North Korea also signed a bilateral military cooperation agreement with each other in 2001.

Recently, Russia has supported US-backed UN Security Council resolutions that punish North Korean nuclear activity with additional sanctions. However, Russian President Vladimir Putin has said that the international community should use a more diplomatic approach to dealing with the Kim Jong-Un regime rather than threaten it the way the United States does.

Trade with North Korea

Both the Russian Federation and the Chinese government have large trade deals with the DPRK. In just the first two months of 2017, Russia boosted its trade with the country by almost 73%. This increase in trade came after China decreased its trade with North Korea due to pressure by the United States.

“We have seen reports about Russia apparently making up for China sanctions on North Korea,” Heather Nauert, a State Department spokeswoman, told reporters, “We are asking Russia to join us in showing North Korea that the only path to a secure, economically prosperous future is to abandon its unlawful programs that endanger international peace and security.”

Russia increased its trade with the hermit kingdom despite UN sanctions that it supported.

Many view Russia's recent attempts to strengthen ties with North Korea is a test to see how committed the United States is to further its own interests in the region.