French President Francois Hollande has vowed to dismantle the “Jungle” migrant camp by the end of the year, during a visit to the port of Calais.
President Hollande said he was determined that the UK should “play its part” in the humanitarian effort.
Hollande was meeting police, port officials, and politicians but is not expected to visit the camp itself.
The fate of the camp and up to 10,000 people living there has become central to France’s presidential campaign.
Hollande said that just because the UK had made a “sovereign decision” – an apparent reference to the UK’s vote to leave the European Union – it was not “absolved from its obligations to France”.
He said he was determined that the UK government would support the humanitarian effort, and said his own government was committed “until the end”.
Between 7,000 and 10,000 migrants and refugees live in the Jungle amid squalid conditions, many of them hoping to enter the UK illegally by hiding on lorries crossing the English Channel.
Hollande paid tribute to the efforts of local security forces, and said he had “a clear message for the traffickers: you won’t be trafficking any more”.
A UK-funded wall 1km (0.6 miles) long is being built along the main road to the port in an attempt to deter would-be stowaways. The UK government has not confirmed the cost, but it is reported to have contributed about £1.9m (€2.2m).
Work began last week, and is due to be finished by the end of the year.