The presidential office has downplayed a U.S. think tank’s report that it identified at least 13 out of an estimated 20 undeclared missile operating bases inside North Korea.

Presidential Spokesman Kim Eui-kyeom told reporters on Tuesday that South Korean and U.S. intelligence authorities are already aware of the bases, having watched them closely with military satellites. 

Kim was commenting on a report released by the Center for Strategic and International Studies(CSIS), which assessed that maintenance and minor infrastructure improvements have been observed at some of the sites.

Kim said the Sakkanmol missile base mentioned in the CSIS report handles short-range missiles and not Scud or intercontinental ballistic missiles. 

The report had said that the Sakkanmol site, which is closest to the border with South Korea and its capital Seoul, appears to be “active and being reasonably well maintained.”

Kim also suggested that it was inappropriate for some U.S. media to describe Pyongyang as being deceptive for having such bases. He said the North never promised to close down the bases and no negotiations exist on having to declare such facilities.