Japanese Finance Minister Satsuki Katayama said on Friday she would meet her counterparts in the United States next week to discuss rare earths supplies, and repeated Tokyo's condemnation of China over its latest export controls. Katayama said she was "very concerned" about Beijing's actions and that she would share Japan's stance at next week's meeting.

Beijing on Tuesday announced a ban on exports of dual-use items to the Japanese military. On Thursday, the Wall Street Journal reported that China had also begun restricting exports to Japanese companies of rare earths and powerful magnets containing them.

Asked about the report, Japan's trade minister Ryosei Akazawa did not comment on whether China had halted Japan-bound export permit reviews, saying Tokyo was analysing the situation.

"What we can say is we're coordinating closely with relevant countries, including the U.S., because China's rare earth-related regulations affect the global economy," Akazawa added.

Finance ministers from the G7 nations will meet in Washington on January 12 to discuss rare earths supplies, three sources familiar with the matter told Reuters.

Asked about China's move, Katayama said recent developments were being addressed and discussed by finance ministers from the Group of Seven.

"These discussions are ongoing because there is a shared recognition, at least among the G7, that securing monopolistic positions through non-market means, and then using that position as a strategic weapon, is unacceptable," she said.

"Such practices are seen as, in a sense, crisis-inducing for the global economy and highly problematic from the standpoint of economic security," she added.