OTTAWA - Prime Minister Stephen Harper says Canada will contribute six CF-18 jet fighters to a NATO air-policing mission as a response to the crisis in the Ukraine.

The jets and ground support staff will be based in Poland.

In addition, the military is sending up to 20 staff officers to bolster the Canadian presence at NATO headquarters in Brussels as the alliance organizes a further response.

On Wednesday, Anders Fogh Rasmussen, the alliance's secretary general, said NATO will deploy additional air, sea and land forces to former East Bloc countries in response to the growing unrest and violence in the Ukraine.

The fighter jets will join warplanes from the United States, Britain, Denmark, Poland, Portugal and Germany, which will be deploying in waves between now and the fall.

Canada is also slated to take part in July in a long-planned, U.S.-led military exercise in Ukraine, known as Rapid Trident 2014, but the government has been not forthcoming about the size and scope of the country's involvement.