The yen was trading back above ¥160 to the dollar late last week and lingered there through Monday, the market testing Japan’s tolerance for a weak currency and daring it to intervene.

Safe-haven buying of the dollar due to the conflict in the Middle East and growing expectations of a rate increase in the United States following stronger-than-expected May jobs data helped weaken the yen.

By midday Monday, the Japanese currency was trading at ¥160.39 to the dollar, its weakest since late April, when Tokyo last intervened to prop up the yen.