For the first time ever, Canada has deployed a Victoria-class submarine on patrol to Asia.
CBC News has learned HMCS Chicoutimi left Esquimalt, B.C., sometime in mid-September for the Asia-Pacific region.
"Her deployment at sea signals the strategic importance of the Asia-Pacific region to Canada," said a military spokesperson in an email.
HMCS Chicoutimi will "provide the government with defence and security options should a timely Canadian response be necessary," he wrote.
The navy would not give exact details about what the sub would be doing, or where.
This represents the first major deployment to the region for any of the submarines purchased from the British government in the early 2000s.
In 2004, en route from Europe, an electrical fire broke out aboard HMCS Chicoutimi when water gushed in through an open hatch while the sub was on the surface.
One crew member died and nine others were injured.
The sub was eventually rescued, lifted onto a barge, and taken to Halifax for repairs. It was then transferred to the West Coast where it underwent an extended maintenance period.
HMCS Chicoutimi officially entered service with the Royal Canadian Navy in 2015.
Two other Canadian vessels recently returned from Asia.
HMCS Ottawa and HMCS Winnipeg, deployed there from March to September, were tasked with participating in Poseidon Cutlass 17, an exercise to "strengthen partnerships" the navy said at the time.
HMCS Chicoutimi's deployment to Asia comes at a tense time in international politics, with ongoing disputes over control of the South China Sea, and leaders from the U.S. and North Korea exchanging insults and threats of nuclear war.
The British-built submarine was originally launched in 1986.