South Korea's and China's foreign ministers agreed Tuesday to step up diplomatic efforts to dissuade Pyongyang from apparent plans to launch a long-range missile test, as the US called on Pyongyang to declare its intentions. South Korea's Ban Ki-moon and China's Li Zhaoxing held closed-door talks for about an hour, talking about strategies for persuading Pyongyang not to test-fire a missile and resuming six-nation talks on North Korea's nuclear weapons program, South Korea's Yonhap news agency reported. Ban asked China to "make efforts for the resolution of this issue by persuading North Korea well," Yonhap reported, citing Lee Hyuck, director-general of the South's Foreign Ministry's Asia-Pacific affairs bureau. China, a key provider of aid to impoverished North Korea, is believed to be the only country that has considerable leverage with the hard-line regime of Kim Jong Il. Six-nation talks aimed at resolving the issue have been stalled since November over a dispute surrounding US financial restrictions on the North.