an aircraft carrier out of the Persian Gulf because of Iran's naval exercises, and Iran would take action if the ship returned. "Iran will not repeat its warning...the enemy's carrier has been moved to the Gulf of Oman because of our drill. I recommend and emphasize to the American carrier not to return to the Persian Gulf", he said. The U.S. Navy spokesman Commander Bill Speaks quickly responded that deployment of U.S. military assets would continue as has been the custom stating: "The U.S. Navy operates under international maritime conventions to maintain a constant state of high vigilance in order to ensure the continued, safe flow of maritime traffic in waterways critical to global commerce." While earlier statements from Iran had little effect on global oil markets, coupled with the new sanctions, these comments from Iran are driving crude futures higher, up over 4%. Pressure on prices reflect a combination of uncertainty driven further by China's recent response – reducing oil January 2012 purchases from Iran by 50% compared to those made in 2011. The U.S. led sanctions may be "beginning to bite" as Iranian currency has recently lost some 12% of its value. Further pressure on Iranian currency was added by French Foreign Minister Alain Juppé who was quoted as calling for more "strict sanctions" and urged EU countries to follow the US in freezing Iranian central bank assets and imposing an embargo on oil exports. On 7 January 2012, the British government announced that it would be sending the Type 45 destroyer to the Persian Gulf. Daring, which is the lead ship of her class is one of the "most advanced warships" in the world, and will undertake its first mission in the Persian Gulf. The British Government however have said that this move has been long-planned, as Daring will replace another Armilla patrol frigate. On 9 January 2012, Iranian Defense Minister Ahmad Vahidi denied that Iran had ever claimed that it would close the Strait of Hormuz, saying that "the Islamic Republic of Iran is the most important provider of security in the strait... if one threatens the security of the Persian Gulf, then all are threatened." The Iranian Foreign Ministry confirmed on 16 January 2012 that it has received a letter from the United States concerning the Strait of Hormuz, "via three different channels." Authorities were considering whether to reply, although the contents of the letter