Humanitarian groups that have been supporting Ukrainian refugees are calling on Ottawa to extend a special immigration program that allows people fleeing Ukraine to temporarily live, work and study in Canada.

The program provides Ukrainians and their families with a visa to stay in Canada for up to three years while they figure out their next steps, but applications are due to close on March 31.

As of Jan. 29, more than 150,000 Ukrainians have arrived in Canada since the Russian invasion of their country last year.

Four organizations that represent Canadian volunteers, hosts and sponsors have written to Prime Minister Justin Trudeau and Immigration Minister Sean Fraser, asking them to keep the door open beyond the planned deadline.

They are also asking that the one-time financial supports the government has been providing to Ukrainian newcomers continue past June, when they are set to expire.

Pathfinders for Ukraine, North America for Ukraine, 4Ukraine.ca and Safe Passage 4 Ukraine have been working to help refugees navigate the immigration system and settle in Canada.