WARSAW (Reuters) - Poland’s prime minister said he wants to visit Russia to commemorate the victims of a World War Two massacre and 2010 plane crash, amid heightened tensions with Moscow after recent comments by Vladimir Putin about Poland’s historical role.

FILE PHOTO: People carry crosses and the portrait of late President Lech Kaczynski during a ceremony marking the eighth anniversary of the crash of the Polish government plane in Smolensk, Russia, that killed 96 people, including President Lech Kaczynski and his wife Maria, outside the Presidential Palace in Warsaw, Poland April 10, 2018. REUTERS/Kacper Pempel/File Photo

Ties have been strained since Poland’s president Lech Kaczynski and 95 others died when their plane crashed at a rarely used airport near the Russian city of Smolensk in April 2010.

The delegation was traveling to mark the 70th anniversary of the Katyn massacre of Polish officers by Soviet troops.

Ties between Moscow and Warsaw have plumbed new lows after a series of comments made by Putin last December about Poland bearing some responsibility for the outbreak of World War Two.

“On April 10, 2020, on the 10th anniversary of the Smolensk disaster, I want to go to Smolensk and Katyn to pay homage to the victims of the terrible Soviet murder in the Katyn forest and the victims of the Smolensk disaster,” Mateusz Morawiecki wrote on Facebook.

“Both of these events have forever changed the history of Poland.”

While the crash, which also killed the central bank chief, top army brass and many lawmakers, initially united Poles in grief, it later came to deepen divisions between liberals and conservatives, including the ruling Law and Justice (PiS) party.

PiS, which is led by Kaczynski’s twin brother, Jaroslaw, blamed Russia for the crash. Some in Poland believe they were murdered.

PiS also says Russia should return the plane’s wreckage to Poland.

An inquiry by the previous government returned a verdict of pilot error, but PiS has said there may have been an explosion.

Presidential spokesman Blazej Spychalski said Foreign Minister Jacek Czaputowicz would meet his Russian counterpart Sergei Lavrov in the coming days to discuss the commemorations.

The Russian Foreign Ministry told the TASS news agency that such a meeting is not being prepared. The Polish foreign ministry did not immediately respond to a request to confirm the meeting.