Mr Trump had railed against US involvement in Afghanistan during last year's election campaign, calling it a "total disaster and vowing to end the 16 year US involvement.

His former chief strategist Steve Bannon fought an ongoing battle with Mr McMaster to keep the president from raising the number of US troops there form the current 8,400.

On Monday, days after Mr Bannon was forced out of the white House, Mr Trump announced his commitment to winning what had become the longest US military conflict.

He gave no details of how many more troops would be deployed but it is likely to be several thousand.

Mr Trump said: "The American people are weary of war without victory. I share the American people’s frustration. In the end, we will fight and we will win."