Long-time Liberal MPs Stephane Dion and John McCallum left cabinet Tuesday and several rookies joined the top ranks as Prime Minister Justin Trudeau remade his government.

The Liberal government’s first cabinet shuffle, announced Tuesday afternoon, confirmed that former International Trade Minister Chrystia Freeland will replace Dion as foreign affairs minister. Freeland’s political portfolio includes the North American Free Trade Agreement (NAFTA), an important economic deal that President-elect Donald Trump has sworn to renegotiate, or tear up, once he enters the White House.

CTV's Ottawa bureau chief Joyce Napier has confirmed that Dion, the former leader of the Liberal Party, has been offered the ambassadorship in France or Germany. It's not known yet which one he'll take, if any.

Dion has asked for several days to consider which posting he'd like; however, whichever role he takes, he's expected to be considered the ambassador to Europe.

Immigration Minister John McCallum is also getting a diplomatic appointment, taking on a challenging envoy role in China.

McCallum and Dion are expected to resign as MPs in order to become ambassadors.

Trudeau commended both outgoing ministers for being “integral parts of our team” and confirmed that he offered Dion “a very important senior position.”

“I need my top people to be out there engaging at the highest levels around the world as well as here at home, and that’s exactly what we’ve put forward,” Trudeau said.

Labour Minister Maryanne Mihychuk is leaving cabinet and will be replaced by Status of Women Minister Patty Hajdu. Hajdu will be replaced by current Democratic Institutions Minister Maryam Monsef.

Ontario MP Karina Gould will become democratic institutions minister.

Trudeau insisted that replacing Monsef with Gould does not signal a change in his promise to replace Canada’s first-past-the-post electoral system by the 2019 election.

“I look forward to having Karina continue on the extraordinary work that Maryam did,” Trudeau said. “This is something that matters deeply to Canadians.”

Francois-Philippe Champagne will replace Freeland as Minister of International Trade.

While Freeland will continue to closely manage Canada’s economic ties with the U.S., Trudeau said that Champagne will have plenty on his plate, including working with Trans Pacific Partnership (TPP) members to increase business opportunities for Canadian companies.

The new immigration minister is Ahmed Hussen, an MP for York South-Weston. Hussen moved to Canada as a refugee from Somalia as a teenager and went on to become a lawyer and community activist.

Hussen became the first Somali-Canadian to be elected to the federal government in 2015.

Rookie MPs promoted

The ambassador to China is a role normally filled by a career diplomat. David Mulroney, a top civil servant at what is now Global Affairs Canada and former adviser to the prime minister, held the position from 2009 to 2012, followed by Guy St-Jacques, another career diplomat. The role has been vacant since October.

It can be difficult to fill the role: the delicate relationship and need to balance both human rights and trade interests takes an experienced hand, while the need to speak Mandarin and the drawbacks to living in Beijing, like heavy pollution, limit the posting's appeal, according to a diplomatic source.

Canada's current ambassador to France, Lawrence Cannon, is a former Conservative foreign affairs minister. He's been Canada's envoy to France since 2012, while postings are generally for three years.

Patty Hajdu was first elected in 2015, after serving as executive director to the largest homeless shelter in northwestern Ontario. She's known around Parliament Hill for being likeable and is very effective in cabinet, a source told CTV News. Her move signifies the government's intention to make changes for women, including adding support systems so fewer have to leave the workforce when they have children.

Two of the new additions are lower profile than their cabinet colleagues. Hussen has an intimate knowledge of the refugee system, having come to Canada from Somalia as one. Since he arrived at age 16, he became a lawyer and co-founded the Regent Park Community Council, helping to secure funding for its revitalization, according to his biography.

Gould has experience in international development, and the source said the government has been impressed with her work ethic and background.

In a news release, Trudeau said Dion has served his country "with integrity and a fierce love of Canada" for 21 years.

"I, and all Canadians, owe him a deep debt of gratitude," Trudeau said in the release.

"I know I will be able to continue to count on his wisdom and his tireless service."

'Politics is not the only way to serve'

In a statement, Dion wished Freeland luck in her new role.

"For one year, Prime Minister Justin Trudeau gave me the honour of being his minister of foreign affairs. As is his privilege, he has just entrusted this great responsibility to another person," Dion said.

The MP for Montreal's Saint-Laurent -- Cartiervile riding said he never planned to spend so much time in politics. He had seen it as "a brief parenthesis in my life," he said.

Dion referred in his statement to his commitment to the environment and the fight against climate change.

"It has been, in fact, an incredible adventure.... I emerge full of energy...renewable! But politics is not the only way to serve one’s country. Fortunately!"