Citing mysterious “health attacks” in Havana, the United States said Friday it is making permanent its withdrawal of 60 percent of its diplomats from Cuba, extending an action that has hurt the island nation’s economy and cramped Cubans’ ability to visit the U.S. Last October, the State Department ordered non-essential embassy personnel and the families of all staff to leave Havana, arguing the U.S. could not protect them from unexplained illnesses that have harmed at least 24 Americans. But by law, the department can only order diplomats to leave for six months before either sending them back or making the reductions permanent. The six months expire Sunday. So the department said it was setting in place a new, permanent staffing plan that maintains a lower level of roughly two-dozen people — “the minimum personnel necessary to perform core diplomatic and consular functions.” The department also said that the embassy in Havana would operate as an “unaccompanied post,” meaning diplomats posted there will not be allowed to have spouses or children live with them in the country. The downsizing of the embassy staff — and a travel warning the U.S. issued warning Americans to reconsider travel to the island — have had significant effects for Cuba’s economy and for its citizens. With fewer employees on hand, the U.S. Embassy in Havana halted visa processing, forcing Cubans who wish to visit the United States to seek visas through U.S. embassies in other countries. The U.S. is also expected to fall far short of granting the 20,000 immigrant visas to Cubans that have been allotted annually for decades. In Havana, hundreds of Cubans waited in line Friday outside the Colombian Embassy seeking visas to visit that country, from which they would have to apply for a separate visa at the American Embassy in Bogota to travel to the United States. Some slept under trees, having traveled to Cuba’s capital from the provinces. “This whole situation is making me very sad,” said Ana Maria Velazquez, an accountant from neighboring Matanzas Province with two children in Florida. She had been waiting for her appointment with Colombian officials for three days. “There should be normal relations between the two countries, but if the U.S. doesn’t want them, at least they should do something that doesn’t hurt people.” Maria Angeles Reyes said she and her husband paid $1,400 for flights to Bogota and lodging there.