OTTAWA — Defence Minister Peter MacKay announced Friday a $9 billion plan to buy 65 advanced fighter aircraft, saying the military needs the F-35 joint strike fighter jets to "meet the threats of the 21st century."

"We need an aircraft that can enable the men and women of the Canadian Forces to meet the increasingly complex demands of the missions that we ask of them," MacKay said at an Ottawa news conference flanked by Public Works Minister Rona Ambrose and Industry Minister Tony Clement.

"This aircraft is the best aircraft that we can provide our men and women in uniform and this government is committed to giving them the very best," he said.

The purchase of the fleet, to be built by American firm Lockheed Martin, is one of the largest in Canadian history.

Ambrose said the government was pressed for time to acquire the single-engine jets, and long-term maintenance contracts would be negotiated at a later date.

"Of course we have some estimates," she said, but would not go into details. "When the aircraft comes off the production line, we expect to negotiate the in-service support costs and, importantly, all of our aerospace companies will also have an opportunity to access and compete for those in-service support costs."

The government's decision to buy the aircraft means Canada can compete for contracts worth billions of dollars for the "global supply chain" of some 3,000 F-35 Lightning II jets, said Ambrose.

Ottawa has invested $168 million into the development of the Joint Strike Fighter Program, which has already produced a return of $350 million in contracts for 85 Canadian companies, research laboratories and universities, Clement said.

Canada joins eight other countries under the U.S-led partnership in the fighter program.

Opposition Liberals and the NDP have lashed out at the government for purchasing the aircraft through a process they consider to be non-competitive.

Liberal Leader Michael Ignatieff said a Liberal government would put the sole-sourced contract on hold and call on the House of Commons defence committee to review the government's "secret, unaccountable decision" to buy the fleet.

NDP MP Malcolm Allen told a news conference Friday there should be a military analysis to determine whether new aircraft, and specifically the F-35, is even needed.

He also said the government should inform the public about the total costs of the purchase, including maintenance.

"If indeed they know what the cost of the estimate is, and they're withholding it from Canadians, then I can only surmise that the price tag would shock Canadians," he said.

MacKay defended the process by which Lockheed was awarded the contract.

He said it was a competitive, "rigorous process" that began under the Liberal government in the early 2000s. He called the party hypocritical for criticizing the purchase.

Liberal defence critic Ujjal Dosanjh said the investment into the program under the Liberals was one of research and manufacturing. "There is absolutely no rush to move on this, as someone said, in the dead of summer, with absolutely zero accountability," said Dosanjh.

The new fighter aircraft will replace the fleet of CF-18s, beginning in 2016. Those fighters, which will be about 40 years old by then, were recently upgraded at a reported cost of $2.6 billion.

MacKay also addressed questions about the cost of the individual jets Canada will purchase, which works out to about $140 million per plane, higher than estimated costs in the U.S. He said the planes are outfitted with on board equipment, including sensors and weapons systems, which account for the cost.

As well, some concerns have been raised in the U.S. about the single-engine aircraft, a worry that was brushed off by MacKay who assured the fighter jets "will match and outperform any dual engine aircraft."

He pointed to Canada's involvement in Norad and NATO as justification of the aircraft, as well as recruiting measures for Canadian Forces.

The Aerospace Industries Association of Canada, the national trade association of Canada's aerospace manufacturing and service sector, praised the government's purchase.

In a release, Claude Lajeunesse, president & CEO of AIAC, said the procurement program "will positively affect the Canadian aerospace industry for decades to come."

The Bloc Quebecois released a statement prior to the announcement asking the Conservative government to ensure some of the contracts to maintain the fleet are tendered to companies based in Quebec.

"Too often, Quebec companies miss out on billions of dollars even though over 55 per cent of jobs in the Canadian aerospace industry are located in Quebec," Bloc MP Claude Bachand said in a statement.

The federal government also announced this week it has restarted the planning process to build two new navy ships, a $2.6-billion project that's also expected to take until at least 2017 to be completed.

The new ships would replace Canada's 40-year-old supply vessels HMCS Protecteur, based at CFB Esquimalt, and HMCS Preserver, based at CFB Halifax.