The yen has weakened close to its lowest level in nearly 40 years amid tensions between the US and Iran that have boosted demand for the dollar as a safe-haven asset. The yen traded at 163.1 per dollar after sliding to 163.23 per dollar on Tuesday, its weakest since December 1986. The dollar index edged down 0.06 percent to 101.05, while Brent crude oil prices rose more than 1.3 percent to 95.31 dollars per barrel after the US launched a new wave of strikes on Iran and the Houthis claimed to have attacked two Saudi oil tankers. Although there are reports that the Bank of Japan may consider raising interest rates sooner than the market expects, that has not been enough to significantly support a yen recovery. Analysts view the dollar's strengthening past 163 yen per dollar as increasing the likelihood of Japanese government intervention, but the absence of strong verbal warnings from officials has left investors unable to clearly gauge the timing of any intervention.