President Donald Trump says Washington hopes to receive more help from Russian President Vladimir Putin in efforts to convince North Korea to abandon its missile and nuclear weapons program.
"The primary point was to talk about North Korea, because we would love to have his help on North Korea. China's helping, Russia's not helping; we'd like to have Russia's help," Trump told reporters on Friday.
Trump spoke with Putin by phone on Thursday.
Later, US Secretary of State Rex Tillerson called for a "sustained cessation of North Korea's threatening behaviour" before talks could occur between Washington and Pyongyang.
"North Korea must earn its way back to the table. The pressure campaign must and will continue until de-nuclearization is achieved," Tillerson told a meeting of the United Nations Security Council.
Tillerson also called on China and Russia to increase pressure on North Korea by going beyond the implementation of UN sanctions.
The Security Council has ratcheted up sanctions on North Korea over its weapons programs since 2006.
Secretary-General Antonio Guterres told the Security Council it was time to re-establish communication channels with North Korea, including inter-Korean and military-to-military channels, to reduce the risk of conflict.
"While all concerned seek to avoid an accidental escalation leading to conflict, the risk is being multiplied by misplaced overconfidence, dangerous narratives and rhetoric, and the lack of communication channels," Guterres said.