The Turkish presidential spokesman has ruled out any change in President Recep Tayyip Erdoğan's scheduled visit to Iran in the first week of April, amid the Saudi-led military offensive in Yemen against the Shiite Houthi rebels that have seized capital Sana'a and several other provinces. Saying there would be no change to Erdoğan's schedule, spokesman İbrahim Kalın said: "On the contrary, these developments have raised the significance of [Erdoğan's] Iran visit." On Thursday, Iranian Foreign Minister Javad Zarif urged for an "immediate stop" to the operations in Yemen, calling them a violation of the country's sovereignty. In a joint statement, five Gulf countries - Saudi Arabia, the United Arab Emirates, Bahrain, Qatar and Kuwait - said the operation "was in response to a request from Yemeni President Abd Rabbuh Mansour Hadi to protect Yemen from the aggression of Houthi militias." Kalın said that the Saudi side has already informed Turkish officials ahead of the operation and Erdoğan has been following the related developments personally since late Wednesday. The Turkish Foreign Ministry said earlier on Thursday: "We support the military operation launched by a coalition force consisting of the countries in the region."