GAO, Mali — Prime Minister Justin Trudeau praised the work of hundreds of peacekeepers during a surprise visit here on Saturday even as he defended his government's refusal to extend their mission several months to help the United Nations. The visit to this hot, dusty camp in northern Mali was Trudeau's first since 250 Canadian troops and eight helicopters arrived this summer to begin providing lifesaving medical evacuations for wounded UN peacekeepers and workers. It will also likely be the prime minister's only visit, as operations are currently scheduled to wind down at the end of July — even though the UN and some allies would like Canada to stay until Romanian replacements arrive in the fall.

Adrian Wyld/Canadian Press Prime Minister Justin Trudeau serves turkey dinner to members of the Canadian Armed Forces in Gao, Mali, on Dec. 22, 2018.

Trudeau flew into Gao aboard a military transport plane — and under a veil of secrecy due to security concerns — with a delegation that included Defence Minister Harjit Sajjan and chief of defence staff Gen. Jonathan Vance. The bright sun and hot desert air belied the fact that the prime minister's visit to this part of Africa was timed to coincide with a pre-Christmas celebration for the troops. "We think often — and we hear this from Canadians — that Canada has a great history of peacekeeping," Trudeau told the assembled troops after helping serve turkey dinners to them. "But it wasn't just because we were nice and polite. It was always because we had consistently demonstrated the capacity to step up and punch well above our weight class — to make a significant and positive impact wherever needed around the world."

Adrian Wyld/Canadian Press A Canadian Armed Forces soldier provides security as medics assist German troops during a medical evacuation demonstration on the United Nations base in Gao, Mali, Dec. 22, 2018.

The Mali mission is the culmination of years of political promises and military planning that started three years ago when Trudeau promised during the last federal election to renew Canada's involvement in UN peacekeeping. While Mali was always seen as a likely destination for Canadian troops, the Liberals took years to commit — because of the mission's danger, and because Donald Trump's victory in the U.S. presidential election diverted the government's attention. More than 175 peacekeepers have been killed in Mali since the UN arrived in 2013, including 22 this year, as drought, extreme poverty and an influx of Islamic militants from surrounding countries have led to escalating violence and insecurity. The Canadians have evacuated only six UN peacekeepers and civilian workers since August. Two civilians were seriously injured by an improvised-explosive device, but military officials say the other cases were non-critical. UN wants Canada to stay longer in Mali: sources Yet even as he emphasized the importance of bringing peace to Mali, the prime minister defended his government's refusal to extend Canada's mission by several months next summer. Romanian peacekeepers will take over in Mali next year, but they aren't expected to arrive until several months after the Canadians have stopped operations. Sources say the United Nations wants Canada to extend its mission to prevent a gap. Trudeau, whose government also has yet to deploy a promised transport aircraft to Uganda and a 200-strong rapid reaction force for the UN, played down the effects of a gap and said Canada and the UN are working to ensure a smooth transition.

Adrian Wyld/Canadian Press A Canadian Chinook helicopter takes off as it provides logistical support during a demonstration on the United Nations base in Gao, Mali, Dec. 22, 2018.

One senior military official said the extreme violence that has gripped Mali for the past several years has shifted southward, away from Gao and toward the largely peaceful capital of Bamako, which the source acknowledged was a concern. Trudeau nonetheless emphasized the importance of the Canadian mission, which also involves moving equipment and troops around Mali's sprawling, desolate landscape, saying it helps the entire UN peacekeeping effort in the country. "They are able to do more because this extraordinarily professional group of Canadians are here to give them the support should an incident happen," the prime minister told reporters. "That level of assurance allows for the entire mission to be more effective." So the way I characterize it to my soldiers every day is that we are the cavalry...Col. Chris McKenna, mission commander Mission commander Col. Chris McKenna echoed that point, saying peacekeepers from other countries rely on the fact that quick medical assistance is available if they run into trouble. "The confidence to drive on the roads here is guaranteed by the fact that someone is coming to get them," McKenna said, referencing the fact that many of the injuries sustained by peacekeepers comes from IEDs and ambushes on convoys. "So the way I characterize it to my soldiers every day is that we are the cavalry: If something bad happens, we are coming to get you."

Adrian Wyld/Canadian Press Canadian infantry and medical personnel disembark a Chinook helicopter as they take part in a medical evacuation demonstration.

Yet there are concerns within the UN and among some allies that a gap will materialize when the Canadians cease operations at the end of July as their Romanian replacements may not arrive until October. The UN has turned to civilian contractors in the past, but peacekeeping officials have been pushing for Ottawa to cover the gap, saying military aircraft are more flexible, cost-efficient and offer better emergency medical help. "Canada extending ... provides both operational and financial benefits to the UN," one UN official told The Canadian Press on condition of anonymity because of diplomatic sensitivities.

Adrian Wyld/Canadian Press Prime Minister Justin Trudeau, centre, makes his way from a Chinook helicopter to watch a medical evacuation demonstration on the UN base in Gao, Mali.