US and allies to 'aggressively' go after ISIS: Obama

"As we've seen, it is still very difficult to detect and prevent lone actors or small cells of terrorists who are determined to kill the innocent and are willing to die. And that's why, as we discuss today, we're going to keep going after ISIL (ISIS) aggressively across every front of this campaign," Obama told reporters after a meeting with his national security team at the Pentagon yesterday.

He said the US and its coalition partners continue to be relentless in their fight against the Islamic State but the group still has the ability to direct and inspire attacks.

"In fact, the decline of ISIL in Syria and Iraq appears to be causing it to shift to tactics that we've seen before, an even greater emphasis on encouraging high profile terrorist attacks, including in the United States," he added.

"We continue to take out senior ISIL leaders and commanders. This includes ISIL's deputy minister of war, Basim Muhammad al-Bajari, the top commander in Mosul Hatim Talib al-Hamduni and in yet another significant loss for ISIL is minister of war, Umar al-Shishani. None of ISIL's leaders are safe and we are going to keep going after them," Obama said.

He said on ground in Iraq, the local forces keep pushing ISIS back and in a major success, Iraqi forces with coalition support finally liberated Fallujah.

"Now they're clearing ISIL fighters from more areas up the Euphrates Valley and Iraqi forces retook the strategic airbase at Qayyarah, just 40 miles from Mosul, now the last major ISIL stronghold in Iraq," Obama said.

"Given the success, the additional 560 US support personnel that I ordered to Iraq last month will help turn this base into a logistical hub and launch bed for Iraqi forces as a push into Mosul," he said.

The US President said the terror groups's leaders know they're going to keep losing and in their message to followers, they're increasingly acknowledging that they may lose Mosul and Raqqah.

"They will lose them. And we'll keep hitting them and pushing them back and driving them out until they do," he said.

Obama said the ISIS turns out not to be invincible and they will inevitably be defeated, but the US also recognises at the same time that the situation is complex and  it cannot be solved by military force alone.

"That's why the United States and countries around the world pledged more than USD 2 billion in new funds to help Iraqis stabilise and rebuild their communities," he said.

In a strong message to Russia, Obama said that the country's direct involvement in these actions over the last several weeks raises very serious questions about their commitment to pull the situation back from the brink.

"The US remains prepared to work with Russia to try to reduce the violence and strengthen our efforts against ISIS and Al-Qaeda in Syria, but so far Russia has failed to take the necessary steps."

"Given the deteriorating situation, it is time for Russia to show that it is serious about pursuing these objectives," he said.

Obama said beyond Syria and Iraq, the US will keep working with allies and partners to go after ISIS wherever it tries to spread and at the request of Libya's  Government of National Accord, they are conducting strikes in support of government aligned forces to retake Sirte from the Islamic State.

We will continue to support the government's efforts to secure their country, he said.

At the same time, the US president insisted that military actions would not be enough for the same.

"So long as their twisted ideology persists and drives people to violence, then groups like ISIL will keep emerging. And the international community will continue to be at risk in getting sucked into the kind of global whack-a-mole, where we're always reacting to the latest threat or a lone actor," Obama said.

"That's why we're also working to counter violent extremism more broadly, including the social, economic and political factors that help fuel groups like ISIL and Al Qaeda in the first place," he said.

Nothing will do more to discredit the Islamic State and its phony claims to being a caliphate, then when it loses its base in Raqqa and in Mosul, he added.

"We are going to keep working with partners, including Muslim countries and communities, especially online, to expose ISIL for what they are - murderers who kill innocent people, including Muslim families and children as they break the Ramadan fast and who set off bombs in Medina," Obama said.