A rift between the right-wing Italian government and Spain's leftist rulers continues to grow over immigration and border security.

It has been over a week since Italy’s conservative government, led by Prime Minister Giorgia Meloni, enacted stricter border controls at air and seaports for any non-EU citizen traveling from Spain. The two countries do not share a land border.

Two days later, Spain’s left-wing government, led by Prime Minister Pedro Sánchez, enacted reciprocal measures on any non-EU citizens traveling from Italy. Even EU citizens need to show their ID to move on, causing travel delays during a month when most Europeans travel, including over 2 million between Italy and Spain.

At issue is border security. More specifically, the five-mile border between Morocco and the Spanish exclave of Ceuta. The illegally cross the border to Ceuta during the late July surge, before Spain and Morocco could reinforce the border to prevent what the EU calls "irregular migration."

Emma Schubart of the Henry Jackson Society told Fox News Digital that Italy’s border checks and Spain’s reciprocal measures "highlight the Meloni–Sánchez divide: enforcement-first versus a regularization program that drew 1.2 million applications."

On July 31, Meloni’s government, in what she called an "extraordinary measure," decided to "temporarily suspend the free movement regime (under the Schengen agreement) in maritime and air connections with Spain, reintroducing border controls," while also offering "to support every European initiative to assist Spanish institutions as needed to restore full control of the Union's external borders." The implementation involved random checks for non-EU travelers.

Even some countries of Europe’s left are taking notice. Meloni teamed up with Denmark’s left-leaning Prime Minister Mette Frederiksen to lead a group of 22 European Union leaders, including Hungary’s new prime minister, Péter Magyar, in a letter calling for an "extraordinary" meeting of EU interior ministers to define a "coordinated European response." The letter placed blame on Spain, noting that "the recent ruling of the Spanish Supreme Court has been used to trigger this attack and abuse (of) our migration and asylum system." They added that the EU "cannot allow mass crossings, the instrumentalization of migration or other hybrid threats to create the perception that illegal entry into the European Union is possible."

Lorenzo Vidino, director of the program on extremism at George Washington University, told Fox News Digital that this "tit for tat" between the two countries could continue "for the foreseeable future." Vidino said EU immigration policies are "complicated" because "there is one policy, but enforcement is by the country," so politics plays a role. "Country A thinks Country B is not enforcing things correctly, so Country A closes the border to create de facto border controls." He said a contributing factor to Italy’s decision may be the large Moroccan population in Italy, especially in northern Italy, which could be a draw for illegal immigrants from Morocco.

Vidino added that these types of internal EU border controls are nothing new. "France also reintroduces these ‘routine checks’ from time to time." Austria continues sporadic checks on land crossings from Slovenia and Hungary and traffic at crossings into Germany can also be miles long due to continued controls there.

And it’s not only outside governments upset with Madrid’s response. Ceuta’s center-right mayor-president, Juan Jesús Vivas, held a press conference Friday, two weeks after the initial incursion, in the city’s Palacio de la Asamblea. He called the situation "unsustainable," saying "Ceuta cannot endure much longer like this." Despite Spanish authorities saying only 5,000 migrants remained in the city, Vivas says that number is closer to 9,000, adding, "Each passing day worsens the situation."

Vivas said he felt "misunderstood and powerless in the face of the lack of legal tools" from Madrid, adding the government is moving too slowly. "I cannot understand that if a part of our territory is invaded… there is no legal mechanism that allows for an expeditious and immediate action for the return of these people who entered this territory illegally and irregularly."

Maldita.es, an independent Spanish fact-checking platform, reports health officials have confirmed cases of scabies, impetigo and an outbreak of gastroenteritis among the migrants. Other news outlets report at least two cases of tuberculosis, but health officials say those affected were treated in Morocco before they crossed the border, and are not contagious. The National Institute of Health Management, the Spanish body responsible for managing healthcare in Ceuta, told reporters that, as of Aug. 11, there were "no confirmed cases of tuberculosis" originating in Ceuta.

Schubart said the EU should look to the U.S. "The U.S. experience is clear, over 8.7 million Southwest border encounters under weakened enforcement produced record surges and secondary pressures. Without consistent external controls, Schengen’s internal free movement erodes."