Speaking by phone, Poroshenko thanked Harper for the assistance that Canada has provided Ukraine with, in particular for its decision to send military instructors and several batches of military equipment to Ukraine.
"We always appreciate your friendly shoulder," Poroshenko said.
Prime Minister Harper said that Ukraine could continue to count on Canada.
The two parties also discussed their positions ahead of the meeting of Group of Seven in Germany in June.
Poroshenko invited Harper to visit Kyiv in the near future. The Canadian prime minister accepted the invitation.
In addition, the parties also discussed a number of issues in Ukrainian-Canadian relations.