Volunteers assist refugees to disembark from a yacht, on which around 250 people crossed a part of the Aegean sea from Turkey’s coast to the Greek island of Lesbos.

The Canadian government on Tuesday pushed back to the end of February its deadline for accepting 25,000 Syrian refugees, in a concession that its original Jan. 1 target was too difficult to meet.

Liberal Prime Minister Justin Trudeau, sworn in this month, made the initial pledge part of his election campaign but a wide array of critics said the goal was unrealistic.

Some provincial and municipal leaders have complained the short timeline did not allow for enough security checks to root out possible ISIS militants. Others said they could not cope with such a heavy flow of new arrivals.

“We just looked at the logistics, we looked at what it would take to bring them in by Jan. 1, and we had options around that,” Trudeau told the Canadian Broadcasting Corp.

“We realized that we wanted to make sure that it was done absolutely right.”

The government will fly in 10,000 refugees by the end of the year and the remainder by end-February.

In another sign of the challenges it is facing, Ottawa cut back its commitment to sponsor all 25,000. Instead, 10,000 will be sponsored privately, with Ottawa aiming to reach its 25,000 target by the end of 2016.

The opposition Conservative Party said it was pleased Trudeau “had abandoned a timeline that was not workable”.

One of the biggest political challenges for the government is the fear that militants could sneak into Canada disguised as refugees. Since the Nov. 13 attacks in Paris claimed by ISIS, an anti-refugee petition launched in Quebec has garnered more than 75,000 signatures nationwide.

Canada will spend up to $510 million (C$678 million) over six years flying in the refugees from Turkey, Syria and Jordan and then helping resettle them. The first flight is due to leave from the region early next month.

The federal government will give priority to complete families, women at risk and gay or transgender people.

It will prioritize single adult men only if they are gay, bisexual or transgender, or if they are accompanying their parents. Private groups will be allowed to sponsor any single adult man regardless of his sexual orientation.

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