British officials say a 4m-high wall will be built to deter migrants trying to reach Britain from the northern French port of Calais.

Home Office Minister Robert Goodwill says the 1km-long barrier is part of a £17 million ($A30 million) package of security measures agreed to by Britain and France.

He says construction will start this month and should be completed by the end of this year.

“We are going to start building this big new wall very soon. We’ve done the fence, now we are doing a wall,” he said.

The wall, which will be funded by the British Government under an agreement struck at a summit in March, will complement a security fence already put up around the port and entrance to the Channel Tunnel.

Green Party MP Caroline Lucas called the wall “monstrous” while campaign group Citizens UK asked Britain to use the money instead to transfer child migrants with families in Britain from Calais.

The fortified railtracks of the Channel Tunnel train in Calais. Photo: Getty.

Richard Burnett, chief executive of Britain’s Road Haulage Association, also told the BBC the plan was a “poor use of taxpayers’ money”.

“[Money] would be much better spent on increasing security along the approach roads,” Mr Burnett said.

Thousands of people from the Middle East and Africa have travelled to Calais, hoping to reach Britain by stowing away on trucks and trains through the Channel Tunnel.

— with AAP