A diplomatic standoff between Italy and France escalated on Wednesday as the two countries traded insults over migration policies.

A day after French President Emmanuel Macron said Rome had acted with "cynicism and irresponsibility" by closing its ports to a migrant ship, Italy's economy minister canceled a Paris meeting with his counterpart, and Prime Minister Giuseppe Conte weighed postponing a meeting with Macron scheduled for Friday.

"We have nothing to learn about generosity, voluntarism, welcoming, and solidarity from anyone," Italian Interior Minister Matteo Salvini told the Senate.

Salvini called on France to apologise and said he was not prepared to take criticism from a country that regularly stopped migrants on their shared border.

France said it has received no formal request from Italy for an apology, and that it believed the planned meeting between Macron and Conte would go ahead.

The row centres on the NGO ship Aquarius, which both Italy and Malta refused to let dock at their ports.

The vessel, carrying 629 migrants, is now heading to Valencia, Spain, escorted by two Italian ships.

Euronews correspondent Anelise Borges is on board the vessel, which is expected to arrive in Valencia in four days.