Theresa May will increase the number of UK troops serving in Afghanistan to more than one thousand ahead of this week’s crucial Nato summit.
The extra 440 non-combat soldiers, largely from the Welsh Guards, will boost the number of British involved with Nato’s mission to 1,090.
It comes amid intense pressure from Donald Trump for allies to live up to the body’s target of spending 2% of GDP.
Ahead of the meeting, the US President ramped up by tweeting that it was “not fair” on the US taxpayer that Washington was paying “many times more than any other country in order to protect them”
At the Summit, Mrs May will call on more of the alliance’s member countries to step up and pay their share.
“Nato is as vital today as it ever has been and our commitment to it remains steadfast,” she will say.
The alliance can rely on the UK to lead by example, not just in meeting the 2% pledge but by contributing our cutting edge capabilities to operations around the world.
“And we will continue to make the case for all allies to follow the UK’s example and meet the 2% pledge.”
The increase will mark the biggest presence of UK military in the region since David Cameron withdrew all combat troops following more than a decade of fighting the Taliban.
Troops will begin being deployed in August of this year, with the remainder to follow by February 2019.