Italy has confirmed it is suspending the EU's border-free Schengen arrangements with Spain in response to a mass influx of migrants into the Spanish enclave of Ceuta from neighbouring Morocco.
The suspension means free movement between the two countries has ended.
Italy does not have a land border with Spain, but the measure will impact people travelling by plane or boat between the two countries.
Italy's interior ministry said in a statement it had also agreed with Paris to strengthen controls along the Franco-Italian land border.
Since Thursday, more than 60,000 Moroccans have stormed the border into Spain's North African enclave, prompting calls for Spanish Prime Minister Pedro Sanchez to declare a national emergency.
After footage emerged from Ceuta, the Prime Minister of Italy, Giorgia Meloni, said: "The images coming from Ceuta are striking and demonstrate, once again, that uncontrolled illegal immigration poses a concrete threat to the security of Europe's borders."
She added: "Italy will not stand by and watch.
"We are convening the relevant bodies, and following these meetings, we are prepared to intervene with extraordinary measures to defend the borders and the safety of citizens, including the suspension of the Schengen Zone with Spain."
Italy have confirmed it is suspending the EU's border-free Schengen arrangements with Spain
| REUTERSThis threat has now been followed through by the European nation.
Italy's Foreign Minister Antonio Tajani said: "Irregular and uncontrolled immigration poses a danger to national security."
"The images coming from Ceuta show how the Madrid Government's decision to grant Spanish, and therefore European, citizenship to over 500,000 irregular immigrants is profoundly wrong and encourages human trafficking.
In April, Spain's Government allowed 500,000 migrants to be given permanent status, giving them a path to citizenship.
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Migrants have flooded from Morocco into Spain's enclave of Ceuta | REUTERSBut Mr Tajani's Spanish counterpart, José Manuel Albares, criticised the remarks, suggesting they were unbefitting of a partner country.
He said: "This message is unbecoming of the Foreign Minister of a partner and friendly country from which we expect European solidarity and not partisan demagoguery."
He also rebutted claims the flood of Moroccan migrants was because of the Spanish Government's decision to grant migrants permanent status.
Earlier this month, Spain's Supreme Court ruled that migrants intercepted at sea while trying to reach Ceuta or Spain's other North African enclave, Melilla, could not be returned to Morocco.
Giorgia Meloni said she was prepared with 'extraordinary measures' to suspend the Schengen Zone with Spain | REUTERSPrime Minister Andy Burnham has issued a statement to reporters on the crisis.
He said: "It is a matter for the Spanish government, and is a cause for concern. We are making contact with the Spanish government to provide support".
Gibraltar has declared it is monitoring Ceuta with "deep concern" but stressed that knock-on effects for the territory remain "extremely unlikely."
Crucially, anyone entering Spain or the Schengen zone without authorisation gains no automatic entitlement to enter Gibraltar, work there, or take up residence, the government said.