Prime Minister Stephen Harper will announce on Friday additional military support in the battle against ISIS militants in Iraq, his office confirmed in a statement Thursday night.

A debate and a vote on the issue are expected on Monday, said Jason MacDonald, Harper鈥檚 director of communication.

He said the prime minister will deliver a statement in the House of Commons and give more details about Canada鈥檚 role in the combat mission against ISIS.

鈥淭his group has made direct terrorist threats against Canada and Canadians, in addition to carrying out atrocities against children, women, and men in the region,鈥� MacDonald said in the statement. 鈥淎s the Prime Minister has said before, when we recognize a threat like this that must be addressed, and that involves Canadian interests, we do our part.鈥�

He said Harper will 鈥渃learly outline鈥� Canada鈥檚 contribution to the combat mission, 鈥渁s well as our ongoing humanitarian support.鈥�

It鈥檚 believed that Harper will send fighter jets to join U.S.-led airstrikes against ISIS.

The government has been considering whether to renew the current 30-day non-combat advisory mission to northern Iraq, which began on Sept. 5. Of the 69 special-forces members committed to the operation, only 26 are currently there.

Extending that commitment into a combat mission doesn鈥檛 require parliamentary approval, but Harper has said that any plan to send Canadian Forces into combat will be put to the House for a debate and a vote.

Earlier Thursday, NDP Leader Thomas Mulcair said the government has offered murky information about Canada鈥檚 role in Iraq so far.

"It would interesting to hear some straight answers from the Conservatives," Mulcair said. "A lot of what they've been telling Canadians has been duplicitous on things that are easily verifiable."

The NDP and the Liberals have not made it clear whether they will vote against a military mission in Iraq.

Liberal Leader Justin Trudeau suggested Thursday that Canada should stick to humanitarian aid.

Although he acknowledged that Canada has a duty to help, Trudeau questioned whether deploying "a handful of aging war planes" is the best way to go.

He suggested that Canada could do more to provide strategic airlift, training, medical support and humanitarian aid for thousands of displaced Iraqis.

With files from The Canadian Press