A currency analyst says the yen's rise was driven partly from remarks by US Republican presidential nominee Donald Trump that expressed concern about the strength of the dollar.

Suzuki Hirofumi, chief foreign exchange strategist at Sumitomo Mitsui Banking Corporation, said: "Mr. Trump had expressed caution against the strong dollar before and this time he stated the same. And then he also mentioned the Chinese yuan and the Japanese yen. That was a surprise for currency market participants."

The Japanese government and the central bank are believed to have conducted yen-buying interventions twice last week to stop the currency from falling.

Suzuki said these actions have curbed the selling of yen by speculators.
He said, "The timing of the believed currency intervention was very surprising for market players, so there seems to be a certain sense of caution that there could be another intervention at any time."

Suzuki said the key in the short-term outlook will be policy meetings of the central banks in Japan and the US at the end of this month.