U.S. Vice President Mike Pence is known to have pressed Russian President Vladimir Putin to enforce sanctions on North Korea when the two met during Pence's Asia trip last week.

Washington Post columnist Josh Rogin wrote an opinion piece titled "When Mike Pence met Vladimir Putin and Xi Jinping," published Thursday, and introduced behind the scenes stories and an interview with the vice president. 

Rogin said that Pence and Putin had three short conversations in Singapore on the sidelines of regional meetings. 

During one conversation, Pence told Putin it was extremely important that Russia enforce U.N. sanctions on Pyongyang in the crucial period before the next U.S.-North Korea summit. 

Earlier, during a closed-door UN Security Council meeting on November eighth, Russia called for the need to ease sanctions on Pyongyang, which Washington quickly opposed and went on to raise issue with Moscow's failure to implement North Korea sanctions.

The two countries have been continuously at odds over the North Korea sanctions issue.