Twenty Spitfires that were buried in Burma during the Second World War are to be restored and repatriated to the UK.
David Cameron struck up the deal with Burmese president Thein Sein in a bid to thaw relations.
The move will see the historic fighter planes located, dug up and shipped back to the UK almost 67 years after they were hidden more than 12m (40ft) below ground under British instruction.
A Downing Street source said: 'The Spitfire is arguably the most important plane in the history of aviation, playing a crucial role in the Second World War.
'It is hoped this will be an opportunity to work with the reforming Burmese government, uncover, restore and display these fighter planes and get them gracing the skies of Britain once again.'
The forgotten aircraft were brought to the attention of the prime minister by a 62-year-old farmer from Scunthorpe, North Lincs, who finally found them at an old RAF base using radar imaging technology in February.
David Cundall has invested 15 years searching for the Mk II planes. His quest has seen him take 12 trips to Burma, costing him more than £130,000 in the process.
Mr Cundall told the Daily Telegraph: 'I’m only a small farmer, I’m not a multi-millionaire and it has been a struggle. It took me more than 15 years but I finally found them.
'Spitfires are a beautiful aeroplane and should not be rotting away in a foreign land. They saved our neck in the Battle of Britain and they should be preserved.'
And Mr Cundall is confident they will be preserved in all their former glory.
'They were just buried there in transport crates. They were waxed, wrapped in greased paper and their joints tarred. They will be in near perfect condition,' he added.
British statesman Earl Mountbatten ordered the RAF to bury the Spitfires in 1945 amid fears they could be either used or destroyed by Japanese forces.
Around 21,000 Spitfires were built during the war effort but only 35 are believed to be in flying condition today.