China is still years away from being able to field a stealth aircraft, despite the disclosure of images indicating that it appears to have a working prototype, Reuters quoted a U.S. Navy official as saying on Wednesday. The Wall Street Journal published images of what it said appeared to show a Chinese J-20 stealth fighter prototype making a high-speed taxi test. The images have also appeared on a number of websites. The publication of the photographs comes just days before U.S. Defense Secretary Robert Gates is due to travel to Beijing. Asked when China would be able to field the jet, U.S. Vice Admiral David Dorsett, director of naval intelligence, said it would be years. Dorsett told reporters the published photos left a lot of questions unanswered. He did not immediately vouch for their authenticity. "In terms of the stealth photos, the IOC (initial operational capability) on the stealth aircraft, it's still not clear to me when it's going to become operational," he said. "Developing a stealth capability with a prototype and then integrating that into a combat environment is going to take some time," he said. -- SPA