"Construction of a UK-funded wall near Calais' so-called Jungle migrant camp will begin very soon, a minister says.
Home Office minister Robert Goodwill said security around the port was being "stepped up with better equipment".
The wall is meant to protect the road from disruption by migrants, thousands of whom live at the Jungle camp.
Work is expected to start this month, with the wall due to be finished by the end of the year.
The BBC understands it will not replace any existing fences.
The government refused to confirm the cost of the wall, but reports suggest a £1.9m price tag - to be paid for out of £17m announced by David Cameron earlier this year.
Speaking to the Home Affairs Committee of MPs on Tuesday, Mr Goodwill said: "The security that we are putting in at the port is being stepped up with better equipment.
"We are going to start building this big new wall very soon. We've done the fence; now we are doing a wall."
But Richard Burnett, chief executive of the Road Haulage Association, called the plan a "poor use of taxpayers' money".
He said funding for a wall "would be much better spent on increasing security along the approach roads"."