A number of foreign cargo planes appeared parked at Pyongyang International Airport on Monday morning ahead of Russian leader Vladimir Putin’s planned arrival, according to NK Pro analysis of satellite imagery.

The Kremlin confirmed late on Monday that Putin will meet DPRK leader Kim Jong Un and stay in North Korea from June 18 to 19. He will also visit Yakutsk in the Russian Far East on Tuesday before flying on to Pyongyang.

Planet Labs imagery shows six large planes of roughly the same size and shape parked across from the airport terminal, three of which are likely Il-76 cargo planes shared by North Korea’s military and national carrier Air Koryo.

This suggests the other three are foreign aircraft, likely Russian. A total of 21 planes were parked in unusual areas of the airport, including 7 km away (4.23 miles) on the northern runway — three more than the 18 that make up Air Koryo’s current fleet.

Putin is known to travel to major summits abroad with a fleet of Il-76 cargo planes, which carry his armored cars and other equipment.

But it is not the first time Russian cargo planes made unpublicized trips to Pyongyang this year, after an Il-76 and An-124 made trips in March, possibly related to ongoing weapons trade between the two countries.

NK Pro previously reported that plane parking aprons nearest the Pyongyang airport terminal were cleared last week, likely to make room for the fleet of Russian planes expected to bring Putin and his delegation. The aprons remained clear on Monday morning.

Satellite imagery also showed an orchestra tent was installed and DPRK flag banners were hung at Kim Il Sung Square over the weekend, indicating a major event will happen within the coming days.

This could be a special parade for Kim Jong Un and Putin to attend celebrating Russia-DPRK relations, and while preparations in the square so far are consistent with preparations for multiple past military parades, there are no other indications that the event will involve weapons displays.

High-resolution Planet Labs imagery taken on Sunday also shows that North Korea built two new parking lots as part of new construction at its most luxurious guesthouse for foreign leaders, the Kumsusan Guesthouse, another sign of rapid planning to accommodate Putin and his delegation. 

Anton Sokolin contributed reporting to this article. Edited by Alannah Hill

Updated on June 17 at 8:26 p.m. KST to reflect confirmation of Putin’s visit to North Korea