A special meeting of Prime Minister Justin Trudeau's national Liberal caucus has been called for next Wednesday, sources say.

The Liberal caucus' regional chairs met Friday afternoon to discuss Trudeau's continued leadership, and next steps. The prime minister was back in Ottawa today but has yet to signal he's ready to address the snowballing calls for his resignation.

During that virtual call, regional caucus representatives were set to ask national caucus chair Brenda Shanahan to consider calling a meeting of all Liberal MPs.

That request has been granted, and it's set to be a lengthy meeting, with Trudeau set to face his MPs for the first time since telling them that he'd be reflecting on his political future over the holidays.

This comes as some MPs are pushing for the prime minister to be presented with a more formal request for his resignation, or to at least put a timeline on deciding on whether he intends to stay on as party leader.

According to a copy of an email sent by Shanahan to the national caucus, the "special hybrid meeting" will be held from 11 a.m. to 5 p.m. EST, with MPs "encouraged" to attend in-person in West Block, or virtually over Zoom.

"When accessing National Caucus by Zoom, members are expected to be alone in a closed confidential space, face visible at all times on screen," reads Shanahan's email, noting the conventionally confidential nature of caucus deliberations.

"Any use of a cellphone or speaking with third parties or other inappropriate activity while on Zoom link will be reason for being disconnected from the Zoom without warning at the Chair's discretion."

Regional caucus meetings will be held in advance, next Monday and Tuesday, the email states.

"They're thinking about … what they do if the prime minister decides that he is not going to announce his departure. How do they … come together and place maximum pressure on the prime minister, make it obvious that he can't stay and secure that departure commitment from him," said Scott Reid, CTV News political analyst and former communications director to then-prime minister Paul Martin.

This meeting comes after calls for Trudeau to step down grew over the holidays from caucus members across the country.

Late Friday, another member of Parliament added his name to that list. Winnipeg South Centre MP Ben Carr said in an open letter that he thinks it's time for the party to head in a different direction. 

"I call for a change in the leadership of the Liberal Party of Canada," Carr wrote. "I do not arrive at this decision easily, nor do I make it happily. Far from it. It is the culmination of daily conversations … over a prolonged period, out of which has emerged a clear belief that it is time for change."

While the caucus is set to reconvene next week, Liberal supporters have already started contemplating the party's leadership rules and the kinds of preparations needed for a potentially expedited race.

"There's a very spirited discussion happening behind the scenes within the Liberal party as to how to select the next leader. People are already looking past the prime minister. And the challenge they have, is that the parliamentary calendar and the constitution of the Liberal party, which dictates how and when you pick a new leader, those things are starting to collide," Reid said.

"There's so little time left on the parliamentary calendar. There's so grave a threat that the government will be defeated in the spring, that the desire to pick a new leader and how they're going to pick it, that's a big topic for discussion."

Trudeau returns to Ottawa

Trudeau, after a week out west with his family, was not expected to be part of today's caucus chairs meeting. However, he did make his first brief public appearance of the new year, visiting the Embassy of the United States in Ottawa to sign the book of condolences for former president Jimmy Carter.

The prime minister did not speak in front of the cameras gathered to capture the moment. He remained largely neutral-faced and had facial hair reminiscent of what he sported while in the thick of managing the COVID-19 crisis.

According to the pool reporter permitted in the room, Trudeau wrote: "As a leader, president, and humanitarian, Jimmy Carter left the world a better place. A fundamentally decent man, he showed what it means to live a life of purpose, to serve. I will always be grateful for his thoughtful advice, and will continue to draw inspiration from his extraordinary life. From your 41 million Canadian neighbours: Merci, Jimmy."

Earlier, the prime minister attended a morning meeting of the Canada-U.S. cabinet committee.

The meeting of ministers, who are tasked with managing relations with the incoming Donald Trump administration, was expected to include some discussion of Finance and Intergovernmental Affairs Minister Dominic LeBlanc and Foreign Affairs Minister Melanie Joly's meeting at Mar-a-Lago last week. No formal read-out from the meeting has been issued.

At a press conference on Parliament Hill Friday morning, Green Party Leader Elizabeth May offered her suggestions for how Canada should be preparing for Trump, and said the country needs strong leadership to stand up for this country in the face of the next president's "51st state" talk.

Asked if she thinks Trudeau can still be that leader, May said "sure," but because "we are not a country that relies on a prime minister solely for leadership."

"Obviously, Justin Trudeau's position is tenuous. That doesn't mean Canada's position is tenuous," she said.

As for whether she thinks it's time for the prime minister to resign, May said that she was hesitant to weigh in.

"I think the prime minister obviously has to consider his role as leader of the Liberal party. But I do think that's an internal question for Liberals," May said.

"I'm not in his shoes, and I think that the resignation of Chrystia Freeland and the circumstances under which she was dismissed from his cabinet right before the fall economic statement calls into question Justin Trudeau's judgment."

With files from CTV News' Judy Trinh, Vassy Kapelos, Stephanie Ha and Mike Le Couteur