The United States is considering blacklisting North Korea's leader Kim Jong Un under a new U.N. sanctions resolution after the country test-fired a second intercontinental ballistic missile, diplomatic sources said Sunday.

But China and Russia are expected to oppose doing so, arguing it runs counter to seeking a peaceful resolution through dialogue.

Washington has apparently suggested that Kim be named to further tighten the screws on Pyongyang, which continues to pursue its nuclear ambitions despite international pressure to stop.