The Lithuanian authorities received a report last Tuesday that the soldiers went missing during a military drill at a training ground in the eastern city Pabrade, near the border with Belarus.

Search and rescue teams worked with heavy equipment and excavators to remove silt from the body of water where the vehicle had been located before eventually towing it out of the swamp early on Monday.

"Three US Army Soldiers assigned to 1st Armored Brigade Combat Team, 3rd Infantry Division were found deceased in Lithuania today, March 31," US Army Europe and Africa's public affairs office said in a statement.

It added that "search and recovery operations continue for the remaining fourth soldier".

The soldiers' identities were being "withheld pending notification of next of kin", the statement said.

"Our hearts are heavy with a sorrow that echoes across the whole Marne Division, both forward and at home," said the division's commanding general Christopher Norrie.

"But the search isn't finished until everyone is home," he added.

"Words cannot express our gratitude to those still working around the clock during these extensive search and recovery efforts and your unwavering commitment not to rest until all are found," he said.

Hundreds of local and foreign troops and other rescue workers including engineers and divers had been involved in a rescue operation to recover the M88 Hercules armoured vehicle.

Lithuania, a NATO and EU member, hosts more than 1,000 American troops stationed on a rotational basis.