WASHINGTON, Rajab 24, 1436, May 13, 2015, SPA -- The Pentagon is considering sending U.S. military aircraft and ships to assert freedom of navigation around growing Chinese-made artificial islands in the disputed South China Sea, a U.S. official said on Tuesday, according to Reuters. U.S. Defense Secretary Ash Carter requested options that include sending U.S. military ships and aircraft within 12 nautical miles of reefs that China has been building up in the disputed Spratly Islands, the official said. Such a move would directly challenge Chinese efforts to expand its influence in the disputed region by literally adding territory through a massive island-building exercise. "We are considering how to demonstrate freedom of navigation in an area that is critical to world trade," the U.S. official said, speaking on condition of anonymity, adding any options would need to be approved by the White House. Carter's request for the development of options including using the U.S. ships and aircraft was first reported earlier on Tuesday by the Wall Street Journal. The Pentagon did not immediately comment. The practice of sending ships and aircraft near the islands would be in line with regular U.S. military "Freedom of Navigation" operations, which it conducted last year to challenge maritime claims of 19 countries, including China. Five countries as well as China lay claim to parts of the Spratly archipelago. They are Brunei, Malaysia, the Philippines, Taiwan and Vietnam. Recent satellite images have shown that since about March 2014, China has conducted reclamation work at seven sites in the Spratlys and is constructing a military-sized air strip on one artificial island and possibly a second on another. Other images have suggested that China is working to extend another airstrip to that length in the Paracel Islands further north in the potentially energy-rich South China Sea, a vital shipping route through which $5 trillion of trade passes every year. "The U.S. and its allies have a very different view than China over the rules of the road in the South China Sea," the U.S. official said. Reuters reported last week China had added about 2,000 acres of land since the start of 2014, according to one U.S. estimate. China drew condemnation from Japan and the United States in 2013 when it imposed an Air Defense Identification Zone (ADIZ), in which aircraft are supposed to identify themselves to Chinese authorities. The United States responded by flying B-52 bombers through the zone in a show of force. --SPA 03:42 LOCAL TIME 00:42 GMT www.spa.gov.sa/w