The United States assumed territorial control over the southern portion of Guantánamo Bay under the 1903 Lease. The United States exercises jurisdiction and control over this territory, while recognizing that Cuba retains ultimate sovereignty. The government of Cuba regards the U.S. presence in Guantánamo Bay as an illegal occupation on the basis that the Cuban–American Treaty "was obtained by threat of force and is in violation of international law."

TLDR yes its considered foreign