SEOUL - Russian Foreign Minister Sergei Lavrov said on Saturday a recently announced guideline on the operation of U.S. nuclear assets on the Korean peninsula is certain to add security concern in the region, South Korean and Russian news agencies reported.

Speaking at a meeting of the Association of Southeast Asian Nations in Laos, Lavrov said he had not been briefed on the details of the plan but said that it is of concern to Russia, Yonhap agency reported.

"Another element of concern is that the United States recently concluded an agreement with the Republic of Korea on joint nuclear planning," Lavrov was quoted as saying by Russian state-run RIA new agency.

"So far we can't even get an explanation of what this means, but there is no doubt that it causes additional anxiety."

The guideline is aimed at responding to nuclear threat from North Korea, the U.S. and South Korea have said.

  - Reuters