Italian Transport Minister Danilo Toninelli accused Malta of shirking its responsibility by not rescuing stricken vessels making the dangerous journey from North Africa.
His comments come as an argument over which of the two European countries should take in 190 migrants rescued this week enters its fourth day.
Malta refused to come to the aid of a migrant vessel which got into difficulties on Wednesday but insists it followed international law.
The boat was in international waters when it broadcast a distress message.
Once closer to the Italian island of Lampedusa, the Italian coastguard vessel Diciotti picked it up.
But the ship has been sat off Lampedusa for the past four days as officials in Italy and Malta continue to argue over where it should dock.
Mr Toninelli, part of Italy’s anti-establishment 5-Star Movement, demanded the European Union open “its ports to solidarity” and agree to take in migrants reduced in the Mediterranean.
The Italian government, which also includes members of the far-right League, vowed to crack down on migration after winning power earlier this year.
More than 650,000 migrants have landed on Italian shores since 2014, though the numbers making the trip are lower now than in the past.
Since taking office in June, Interior Minister Matteo Salvini has spearheaded a campaign to stop humanitarian rescue ships operating out of Italy’s ports.
He has also refused to allow some boats to dock. In June, he turned away the Aquarius rescue ship which was carrying 630 migrants.
Meanwhile, Malta rescued two different migrant boats which ran into difficulties in its waters this week.
One boat on Monday was carrying 114 people and a second on Saturday had about 60 people on board.
Maltese Prime Minister Joseph Muscat insisted the migrants from the latest boat are Italy’s responsibility.
He said: “They are now on board a military vessel, which practically means on Italian soil. I expect that Italy would ask other EU states to help, it is up to them, but Malta followed international law.”
Despite European Union leaders striking a migration deal at a summit in June, the issue over who should take responsibility for those rescued at sea is far from settled.
The agreement would involve the creation of secure processing centres in North Africa which would handle applications for asylum outside of the bloc.
But the plan has already been hit by a series of major setbacks as most countries on the North African coast have refused to accommodate the facilities.