US President Barack Obama says he will not hesitate to take action against Islamic State (IS) militants in Syria as well as Iraq, BBC reports.In a nationally televised speech outlining his strategy against IS, he said that any group that threatened America would “find no safe heaven”.He also announced that 475 US military personnel would be sent to Iraq but said they would not have a combat role.IS controls large parts of Syria and Iraq after a rapid military advance.Its fighters have become notorious for their brutality, beheading enemy soldiers and Western journalists on video.The US has launched over 150 airstrikes against the group in Iraq and provided arms to Iraqi and Kurdish forces fighting against IS.In a 15-minute speech shown at peak time in the US, President Obama vowed that America would lead “a broad coalition to roll back” IS.