Senior South Korea, U.S. and Japanese diplomats will likely meet in Washington later this week to discuss ways to deal with North Korea's long-range rocket launch plan, a source here said Monday.

Lim Sung-nam, South Korea's special representative for Korean Peninsula Peace and Security Affairs, is scheduled to arrive here on Wednesday for meetings with his American counterpart Glyn Davies and other officials.

Shinsuke Sugiyama, the director general of the Japanese foreign ministry's Asian and Oceanian Affairs Bureau who serves as Tokyo's point man on Pyongyang, will also visit Washington.

"Chances are high that they will hold a trilateral meeting," the diplomatic source said on the condition of anonymity. "The exact date and time have not been decided yet with related consultations still under way."

If the envoys gather, they will talk about efforts to persuade North Korea not to go ahead with the launch, added the source.

"They will also discuss the next steps in case of a failure to do so," the source said. (Yonhap News)