"It's time to wage war on this phenomenon," Marine Le Pen told inhabitants of Calais on Friday. "Calais has been abandoned" by the government in the face of an exponential rise in the number of illegal immigrants", she declared.
The Far right leader pledged her "solidarity" to residents, mired by migrant unrest. Earlier this week, riot police used teargas to push back hundreds of immigrants seeking to jump on to trucks bound for Britain.
Marine Le Pen called for urgent reintroduction of internal border controls that were banished across much of Europe.
But many believe she is trying to capitalize on recent tensions to consolidate her popularity, after her Front National party won huge gains in European elections on a wave of anti-immigration rhetoric.
Roughly 2,300 immigrants, many of them from Africa, are roaming the streets and sleeping in makeshift camps in and around Calais while waiting to attempt the final leg of their bid to reach Britain.
On Friday, France's Interior Minister announced he would send 100 extra police officers to Calais in a bid to end the ongoing migrant unrest around the northern port.
Marine Le Pen was eventually forced to shorten her vist after being booed.