This Dec. 5, 2018 image provided by DigitalGlobe provided on Tuesday, March 5, 2019 shows a satellite image of North Korea's Sohae facility. AP-Yonhap

North Korea's nuclear weapons and ballistic missile programs have remained intact as the country has developed new means to evade sanctions, a United Nations panel said Tuesday.

North Korea's main nuclear facility in Yongbyon has remained active, with its 5-megawatt reactor in operation since December 2015, according to an annual report by a panel of independent experts for the U.N. Security Council committee monitoring sanctions implementation on the North.

It said satellite imagery of the complex from February to November 2018 showed the excavation of water channels and the construction of a building near the reactors' water discharge facilities.

A new building could also be seen on the west side of the light water reactor, the panel said.