Britain has been forced to cancel a planned military training exercise in Kenya after Nairobi declined to ratify a new bilateral defence agreement, with the two countries locked in a dispute over legal jurisdiction, troop accountability and the terms of Britain's military presence in the East African nation.

The decision means a major exercise involving the British Army's 1st Battalion, Duke of Lancaster's Regiment, scheduled to begin in September, will no longer take place in Kenya.

Instead, the troops will train at an alternative location outside the country after the necessary licences for the exercise were not granted.

The development marks a rare setback for one of the United Kingdom's longest-running military partnerships in Africa, with Kenya seeking stronger legal authority over British personnel stationed in the country.

Why Kenya is holding up the defence deal