The Cuban government has reinstated a travel permit requirement restricting doctors leaving the Caribbean island to go to the United States.

The policy was announced on Tuesday following a meeting between U.S. and Cuban negotiators in Washington to address a crisis in Cuban migration, which is at its peak level in at least two decades. Cuban doctors seeking to head to the U.S. are now required to get permission from Health Ministry officials in order to leave the country, CTV News reported.

Authorities said that Cuba's health service have been "seriously affected" by the huge number of doctors moving abroad since President Raúl Castro permitted new freedoms in 2013 for social and economic reforms, BBC reported.

Many Cuban doctors listed low wages, poor working conditions, and the possibility of good job compensation as their main reasons for migrating to other countries, CTV News wrote. The Cuban government laid the blame on the U.S. policy called "wet-foot-dry-foot," which grants automatic legal residency to Cuban immigrants. This also comes with special fast-track benefits for doctors who ditch medical missions overseas.

Cuba's government criticized this policy for pushing Cuban health professionals to abandon their nation and its needs for medical care.

"It must be recalled that the United States government has historically used its migratory policy as a weapon against the Revolution, and has, for political reasons, encouraged emigration from Cuba," according to the government's statement published in the official newspaper, Granma, as quoted by BBC.

According to Cuban officials, anesthesiology, neurosurgery, obstetrics, and gynecology and neonatal care are among the specialties largely affected by the huge wave of doctors leaving the country, CTV News listed.

Cuba regards free and universal health care system as one of the greatest achievements of its socialist revolution, the news outlet noted. Overseas medical missions are among of its most vital sources of foreign exchange for the Cuban government, which obtains tens of thousands of dollars annually in cash or commodities for each doctor it sends abroad. At least 100,000 Cubans have emigrated to the U.S. over the past two years.

Castro's administration, which vows to ease economic and travel restrictions between the U.S. and Cuba, announced in September that it would welcome back doctors who abandoned their duties while working overseas on programs sponsored by the island's government, BBC further reported. Doctors would not suffer punishment or loss of status and would be offered their jobs back.

The Cuban government said it has some 50,000 health workers -- half of them are doctors -- involved in health projects in 68 countries, BBC noted. Critics said that the highly-trained medical professionals are underpaid.