Japan's top currency diplomat warned investors against significantly pushing up the yen, signalling that Tokyo was ready to intervene in the currency market if excessive yen gains threatened to hurt the export-reliant economy.

Yoshiki Takeuchi, Japan's vice finance minister for international affairs, said Tokyo was in regular contact with overseas authorities to respond to volatile market moves.

"As we have been saying, it's necessary to take action based on the G7 and G20 agreement if currency moves have a negative impact on the economy and financial markets," Takeuchi told reporters, when asked whether Japan could intervene in the currency market to stem excessive yen rises.

He made the comments after a meeting of top officials from the Ministry of Finance, Bank of Japan and the Financial Services Agency, which is held occasionally to discuss market developments.