South Korea and the United States are calling on Japan to share the content of its inter-governmental talks with North Korea.
Officials from Tokyo and Pyongyang have been discussing a number of issues including the repatriation of Japanese nationals abducted by Pyongyang in the 1970s and 80s.
Sources privy to this week's trilateral talks in Washington say the South Korean and U.S. nuclear envoys don't want Japan to make secret, two-way contact with North Korea.
This after the Japanese envoy told them how the discussions had been progressing.
South Korea and the U.S. are reportedly concerned the Japan-North Korea talks could make it more difficult to pressure Pyongyang over its nuclear program.
Tokyo says it just wants to speed up the repatriation of its nationals.
North Korea and Japan held their first government level talks in more than a year at the end of last month.