The US has agreed to reveal to the UK technical details of the Joint Strike Fighter, satisfying UK demands before committing to the £140bn project.
The maiden flight is expected within days
Defence chiefs had been under pressure not to commit to the project unless the US released details to allow the UK to operate the jets independently.
A memorandum of understanding with the US has now been signed allowing the programme's next stage to go ahead.
The dispute had threatened to end UK plans to buy 150 of the aircraft.
In a written statement to Parliament on Tuesday, Defence Secretary Des Browne said: "We have always been clear that the UK would only sign the MoU [memorandum of understanding] if we were satisfied that we would have operational sovereignty of our aircraft.
"We have today received the necessary assurances from the US on technology transfer, which we would require to operate the aircraft safely and maintain, repair and upgrade it over its operational life."
Mr Browne said signing the memorandum "does not, however, formally commit the UK to buying any aircraft".
His statement added: "Our associated increase in financial commitment at this stage is £34m."
The F-35 Joint Strike Fighter, the world's most expensive military project, is expected to take to the skies for its maiden test flight within days.
The £140bn ($276.5bn) Anglo-US project will supply the armed forces of the US, Britain and several other countries.
Last week the defence select committee warned the government not to proceed with buying the fighter planes unless they could operate them independently.
Earlier this year, the government also expressed concerns about the deal.
The US will account for the lion's share of the Lockheed Martin-designed military planes, with 2,400 in service by 2027, while the UK is expected to take delivery of 138 fighters.
Britain's BAE Systems is one of the key players in the aircraft's development, and has put $2bn (£1.02bn) into the project.
The Ministry of Defence is planning to get a variation of the JSF for use by the Royal Navy on two future aircraft carriers.
Shadow Defence Secretary Liam Fox said the UK-US memorandum was "good news for Britain's national security".
He added: "The real importance of this lies in its implications for our strategic commitment.
"It reinforces the concept that our primary defence alliance is with the United States."
F-35 JOINT STRIKE FIGHTER
The JSF is a supersonic stealth aircraft
Built to replace F-16s, F/A-18 Hornets and Harriers
Each plane costs approximately $45m
Variations include one for aircraft carriers and a jump-jet
Possible weapons are 'smart' bombs, air-to-air missiles and the UK's Storm Shadow cruise missile