The Liberals aren’t certain they’ll meet their target of getting 10,000 Syrian refugees to Canada by the end of the year, Immigration Minister John McCallum said Wednesday, owing to the “human and weather element.”

However, they still believe they’ll reach their target of 25,000 by the end of February.

“I am convinced that by the end of the year, 10,000 or more Syrian refugees will be confirmed certified as Canadian permanent residents. The issue is whether all of those 10,000 Syrian refugees will have arrived in Canada — will have their feet on Canadian soil by December 31st,” McCallum said in a press conference at the National Press Theatre in Ottawa.

“That certainly remains our target, we are working day and night to achieve it. But there are certain factors outside our control, like the weather…and human nature.”

Thought McCallum said a flight was en route to Montreal with 298 additional Syrian refugees, and many more flights will be arriving in what remains of 2015, he couldn’t say exactly how many.

“Certain days there will be one flight, other days there will be two or even three. I can tell you the maximum capacity of the Montreal airport is two flights per day and in Toronto it’s three flights per day. So the maximum would be five flights a day,” he explained.

“Every day you’ll get the most recent news on those flights.”

During the federal election campaign, then Liberal leader Justin Trudeau committed to resettling 25,000 Syrian refugees by the end of the year. In late November, the government pushed back the deadline to resettle 25,000 to the end of February, committing instead to resettle 10,000 by January 1.

Though the Conservatives were pleased to see the Liberals take more time to ensure applicants are properly vetted — having themselves set a target during the campaign of 10,000 by September 2016, on Tuesday the party’s immigration critic, Michelle Rempel, took to Twitter to criticize the government’s moving target.

The LPC has shifted the goalposts on their refugee target so many times they aren't even on the field anymore. — Michelle Rempel, MP (@MichelleRempel) December 23, 2015

If they aren't even close to meeting their 25,000 target, what other details are being overlooked? Housing? Screening? Cost? — Michelle Rempel, MP (@MichelleRempel) December 23, 2015

The Conservatives weren’t alone.

In an interview with Maclean’s published Monday, NDP Leader Thomas Mulcair took aim at the Liberals’ handling of the file.

“During the election campaign, before we made our commitment in the NDP to bringing in 10,000 before the end of the year, we talked to the top experts. We talked to the top academics. We looked at what the United Nations was asking of Canada. We talked to NGOs. They all said it’s extremely ambitious, but 10,000 is plausible between now and the end of the year,” he said.

“The next day the Liberals held a press conference to attack us. What a bunch of chisellers. Ten thousand – we can do 25,000 by the end of the year! Barely a couple of days after the [Trudeau government’s] swearing-in they said, ‘Oh, by the way, 25,000 is totally unrealistic, maybe 10,000.'”

But now it seems even that promise will be difficult to keep. According to the government’s numbers, as of Tuesday 1,869 Syrian refugees had arrived in Canada and an additional 2,393 applications have been finalized.

The flight McCallum mentioned Wednesday will bring the total to more than 2,000, but far more will have to arrive in the next eight days to get them over 10,000.

“We are moving heaven and earth to get them here as quickly as we can, but to do it in a way that is correct and appropriate and takes due concern for security, medical, and other issues…We are sticking to our target of 10,000 of the end of the year, but there are challenges and it’s less possible to guarantee that in it is the 25,000 target,” he said.

“I do not think Canadians are getting all anxious and upset because instead of being here by the end of December, they’ll be here by the end of February.”