SEOUL, June 17 (Yonhap) -- South Korean President Park Geun-hye told U.S. President Barack Obama on Monday that holding talks with North Korea for the sake of talks would only give the communist nation more time to advance its nuclear programs, an official said. Park made the remark during a 20-minute phone conversation with Obama, the official said, a day after North Korea proposed to hold high-level talks with the U.S. saying it wants to have broad and in-depth discussions on defusing military tensions and other issues.

Lee Chi-dong WASHINGTON, June 16 (Yonhap) -- The White House said Sunday North Korea should first prove its seriousness about dialogue through actions, "not nice words," effectively turning down the communist nation's offer of bilateral negotiations without "preconditions" attached. "Those talks have to be real. They have to be based on them living up to their obligations, to include on proliferation, on nuclear weapons, on smuggling and other things," said Denis McDonough, President Barack Obama's chief of staff.

The United States will only engage in "real" talks with North Korea and will judge actions, not Pyongyang's "nice words" about wanting high-level negotiations, a senior US official said Sunday. Any talks "have to be based on them living up to their obligations" on proliferation, nuclear weapons, smuggling and other issues, White House Chief of Staff Denis McDonough told CBS News's "Face the Nation."

Japan, the United States and South Korea agreed Saturday to cooperate in curbing North Korea's nuclear and missile development, as well as its provocative actions. Japanese Defense Minister Itsunori Onodera, U.S. Defense Secretary Chuck Hagel and South Korean Defense Minister Kim Kwan Jin shared the view North Korea's de-facto long-range missile test in December and its third nuclear test in February pose a "serious threat" to security in Northeast Asia and the world, the three ministers said in a joint statement issued after a meeting in Singapore.