were not divulged. The United States had previously announced its intention to warn Iran that closing the Strait of Hormuz is a "red line" that would provoke an American response. Gen. Martin E. Dempsey, the chairman of the Joint Chiefs of Staff, said this past weekend that the United States would "take action and re-open the strait", which could be accomplished only by military means, including minesweepers, warship escorts and potentially airstrikes. Defense Secretary Leon E. Panetta told troops in Texas that the United States would not tolerate Iran's closing of the strait. Nevertheless, Iran continued to discuss the impact of shutting the Strait on world oil markets, saying that any disruption of supply would cause a shock to markets that "no country" could manage. By 23 January, a flotilla had been established by countries opposing Iran's threats to close the Hormuz Strait. These ships operated in the Persian Gulf and Arabian Sea off the coast of Iran. The flotilla included three American aircraft carriers (the , the and ) and three destroyers (, , ), seven British warships, including the destroyer and a number of Type 23 frigates (, , and ), and a French warship, the frigate La Motte-Picquet . On 24 January, tensions rose further after the European Union imposed sanctions on Iranian oil. A senior member of Iran's parliament said that the Islamic Republic would close the entry point to the Persian Gulf if new sanctions block its oil exports. "If any disruption happens regarding the sale of Iranian oil, the Strait of Hormuz will definitely be closed," Mohammad Kossari, deputy head of parliament's foreign affairs and national security committee, told the semi-official Fars News Agency. 2015 seizure of MV Maersk Tigris On 28 April 2015, IRGCN patrol boats contacted the Marshall Islands-flagged container ship Maersk Tigris, which was westbound through the strait, and directed the ship to proceed further into Iranian territorial waters, according to a spokesman for the U.S. Defense Department. When the ship's master declined, one of the Iranian craft fired shots across the bridge of Maersk Tigris. The captain complied and proceeded into Iranian waters near Larak Island. The US Navy sent aircraft and a destroyer, USS Farragut, to monitor the situation. Maersk says they have agreed to pay an Iranian company $163,000 over a dispute about 10 container boxes transported to Dubai in 2005. The court ruling allegedly ordered a fine