Foreign Minister Enzo Moavero Milanesi said Italy would continue to accept vessels for five weeks while the EU renegotiated its existing policy.
Italy's new right-wing government has taken a hard line on migration.
The country is the main point of entry for Africans coming to Europe by sea, but wants the burden of migrant arrivals to be shared among EU states.
Speaking on Monday after talks with his German counterpart, Heiko Maas, Mr Milanesi said Italy's ports would remain open until a solution was reached to prevent "all rescued people from landing in one country".
In June, Italian Prime Minister Giuseppe Conte warned that the Schengen Zone of visa-free travel across much of Europe was in danger if the EU failed to reach a consensus on the issue of migration.
The same month, the Italian government refused to allow more than 600 migrants aboard the charity rescue ship Aquarius to disembark. The ship was eventually diverted to a Spanish port.
Another charity ship, Lifeline, was only able to dock in Malta after eight EU states agreed to take in a number of those on board. Italy had again refused to allow the vessel to enter its ports.
However, the policy has come under scrutiny after a Spanish charity accused the Libyan coastguard of abandoning three migrants, including a woman and child who died, and blamed Italy for its alleged support for the Libyan action. Both countries denied the charity's accusations.
BBC
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