The company operates services to Przemyśl, where passengers can transfer to trains traveling to Ukraine.
The Hyundai Rotem high-speed train will resume operation on 10 June.
Women's compartments will be test-operated for several months, after which a decision on scaling up will be made.
An SKPL train performed a test trip on the Lublin - Rava-Ruska route in early April.
The company is offering an alternative route from Austria and Hungary to Ukraine.
Poland will need several months to establish customs and border controls after the test operation, after which the date of the launch of regular train services will be announced.
Four trains will be sent to Ukraine by the summer and an additional 8 during the year.
The trains operated on the Helsinki - St. Petersburg route in 2010 and are suitable for Ukraine’s rail tracks.
The Polish and Ukrainian sides apparently cannot agree on the launch of traffic on the border railway section.
The Polish company refused to repair the diesel train because of the Russian and Belarusian aggression against Ukraine.
Ukrzaliznytsia has reported another successful day in terms of the punctuality rate of long-distance trains.
The train will consist of two vintage steam locomotives from 1954 and five passenger cars.
Ukrzaliznytsia has scheduled an additional train on the route between the capitals of the two countries for the winter holiday period.
The Mukacheve - Košice train resumed operation on December 11.
Trains will run in both directions twice a day.
It announced plans to move production in March.
The train will pass through Poltava, Kharkiv, Balakliia, and other cities, offering residents of liberated Izium a convenient rail link with Kyiv via a night train.
The CFTS reprints the New York Times editorial about the outstanding courage of the Ukrainian railroad workers who gave Ukraine and Ukrainians a shoulder at the most critical moment in the country's modern history.
Ukrzaliznytsia has restored the rail link between Kyiv and Mykolaiv.