As the United States pressures China to enforce United Nations sanctions on its ally North Korea, Washington is concerned that Russia could fill any vacuum left by Beijing.
The U.S. ambassador to the United Nations, Nikki Haley, told lawmakers in Washington on Tuesday: "I'm concerned that Russia may backfill North Korea. We don't have proof of that, but we are watching that carefully."
While Washington has urged countries to downgrade ties with Pyongyang over its nuclear and ballistic missile programs, a cross-border ferry service was launched in May between North Korea and Russia. Russian President Vladimir Putin has said the world should talk to, rather than threaten, North Korea.