LABUAN (The Star/Asia News Network) - Islamic State in Iraq and Syria (ISIS) militants pose a serious security threat to Sabah if no proactive measures were taken to stop them, said Malaysia's Defence Minister Hishammuddin Tun Hussein on Friday.

"I think it is under control at the moment, but if we do not continue to take proactive measures, it can become a very serious threat," he told reporters at the Royal Malaysia Air Force airbase in Labuan.

Hishammuddin is on a three-day working trip to Sabah beginning Friday in order to evaluate the preparation and capability of the defence and security system in the state.

"At least we are bracing ourselves against any threat, a far cry from the situation in Iraq and Syria when it is too late to take action?," he said.

"Once it has happened, the situation (in Iraq and Syria) is costing the countries a lot of money," Hishammuddin said.

According to him, the coalition partners have so far found no firm solution in curbing the ISIS militants in Syria and Iraq.

"What we are trying to do is to have proactive measures here in Sabah so that it does not happen here," Hishammuddin added.