A U.S. expert has reportedly said that a new nuclear facility North Korea is apparently building at its main Yongbyon nuclear complex is located about two kilometers from the existing facility.

According to Japan’s Kyodo News on Thursday, professor Jeffrey Lewis, an expert on nuclear proliferation at the Middlebury Institute of International Studies, presented the analysis citing Planet Labs satellite imagery from Wednesday last week. 

Lewis said the new facility appears to have a central hall, likely housing uranium enrichment centrifuges, with offices and support facilities around it. 

He added that it is similar in size and layout to the Kangson enrichment facility seen in photos taken in 2002.  

The report comes days after International Atomic Energy Agency Director General Rafael Grossi said in a report to the body’s board of governors that the nuclear watchdog is monitoring the construction of a new building at Yongbyon, which has dimensions and features similar to those of the Kangson enrichment plant.