"We talk with South Korea all the time and coordinate with them on sanctions on a host of countries. We've talked to a number of partners about increasing the pressure on Russia. This is part of that normal outreach," deputy State Department spokeswoman Marie Harf said at a regular briefing.
Harf was responding to a question about discussions that Peter Harrell, deputy assistant secretary for counter threat finance and sanctions, held in Seoul on Tuesday.
"We believe that the more countries that impose costs on Russia, the more effective those sanctions are, the more people you get on board for them. It's part of those discussions," she said.
The U.S. believes that Malaysia Airlines Flight 17 was shot down on July 17 in eastern Ukraine by pro-Russian rebels with a missile supplied by Russia. Moscow has denied any involvement.
President Barack Obama announced fresh sanctions on Russia earlier this week. (Yonhap)