The Royal Navy's entire fleet of Harrier jump jets, the British plane controversially scrapped in last year's defence review, has been saved – by the US military.

All 74 of the planes, which were permanently grounded by the Strategic Defence and Security Review (SDSR), are to fly again for the US marines, in a deal that is expected to be closed within a week.

The Ministry of Defence said negotiations were continuing but were in their final stages. And reports in the US suggested the marines were already confidently preparing for the Harriers' arrival.

The sale of the Harriers is bound to raise fresh questions about the wisdom of retiring the much-admired aircraft, which the Americans intend to use until 2025.

Speaking to the NavyTimes, Rear Admiral Mark Heinrich, chief of the US navy's supply corps, said buying the Harriers made sense because many of the jets had been recently upgraded, and the US already had pilots who could fly them.

"We're taking advantage of all the money the Brits have spent on them," he said. "It's like we're buying a car with maybe 15,000 miles on it. These are very good platforms. And we've already got trained pilots."

The US military already has its own fleet of Harriers, and converting the British planes to fire American missiles can be done relatively easily.

The price of the deal has not been disclosed, but Heinrich said the US was paying $50m (£32m) for spare parts alone.

The British Harriers have been kept in storage at RAF Cottesmore, in Rutland, where they have been maintained prior to sale.

Their retirement was criticised when the SDSR was published, last year, and again when British forces became involved in operations to defend Libyan civilians during the country's revolution.

The MoD has maintained, however, that it had no choice, because of cost-cutting forced upon a department where budgets were out of control.

Rear Admiral Chris Parry, a critic of SDSR, said: "The issue is not that the US marines are buying the Harriers: it's that the US still thinks that the Harriers are viable aircraft. They still think there is a need for them."

The MoD said it was negotiating the best deal it could, and that scrapping the Harrier would save hundreds of millions of pounds over the next decade.