Researchers have identified another secret ballistic missile base in North Korea, one of an estimated 20 that the communist state has not declared. The discovery comes just days after the White House announced that President Trump would hold a second summit with North Korean leader Kim Jong Un in late February. Trump on Saturday told reporters that “things are going very well with North Korea,” and that Washington and Pyongyang “have made a lot of progress as far as denuclearization is concerned.”

The secret base, called Sino-ri, was disclosed in a report released Monday by the Center for Strategic and International Studies (CSIS), a D.C.-based think tank. CSIS reported on the existence of 13 of the 20 undeclared missile bases in November. The newly identified facility is one of the oldest in existence, according to Monday’s report. Sino-ri is located 132 miles north of the demilitarized zone that divides North and South Korea and provides “an operational-level nuclear or conventional first strike capability against targets located both throughout the Korean Peninsula and in most of Japan,” according to the report.