WASHINGTON (CBSDC/AP) — Sen. Rand Paul, R-Ky., believes that the Islamic State of Iraq and Syria terror group has declared war against the United States.

Speaking to Fox News on Wednesday, the potential Republican presidential contender believes President Barack Obama needs to come before Congress to make a case to take action against ISIS.

“If I had been president, I would have called a joint session of Congress this August, brought everybody back from recess and said, ‘This is why ISIS is a threat to the country. This is why I want to act, but I want to do it in a constitutional manner,’” Paul explained. “I want the entire American public to come together, to galvanize support, and say, ‘You know what, this is something we can’t take. We’re not going to let our enemies behead our journalists. We’re not going to let them become strong enough to attack our embassy.’”

Calls for Obama to take more action against ISIS have increased dramatically after the terror group beheaded two American journalists, James Foley and Steven Sotloff. Obama was harshly criticized for stating during a press conference last week that the administration does not have a strategy yet to deal with ISIS.

Paul blames Obama for making the terrorists stronger by going after former Libyan leader Moammar Gadhafi and Syrian President Bashar Assad.

“I would argue that intervention isn’t always the answer. I think in Libya it’s made the world less safe. It’s made the jihadist groups more emboldened in Libya. I would say the same thing in Syria,” Paul told Fox News. “I think that President Obama’s support for the Islamic rebels has allowed ISIS to grow stronger in Syria, and they never would have grown this strong without … their allies getting weapons from both us, Saudi Arabia, Kuwait, Qatar, so really, we have done a disservice and created chaos that has allowed the jihadists to grow stronger.”

Paul insists that Obama is weakening the presidency by not coming before Congress to confront ISIS.

“What should be going through his mind is that he should be obeying the Constitution, which he means he should come to Congress. We should have a big debate in Congress and with the American people and he’s not going to do it,” Paul told Fox News. “But therefore he actually weakens the presidency, weakens America, and weakens everything we stand for if he’s not willing to obey the constitution.”

Paul added that the U.S. should defend itself the way the Constitution intended.

“I’m neither an isolationist nor an interventionist. I’m someone that believes in the Constitution and believes that America should have a strong national defense and believes that we should defend ourselves,” Paul said. “But when we do it, we should do it the way the Constitution intended.”

Obama administration officials maintained that the U.S. will not launch a ground war against the Islamic State militants. But they stopped short of ruling out airstrikes against the group in its safe haven in Syria, as the U.S. has resisted for years. The U.S. has been conducting airstrikes against ISIS in Iraq.

Obama has “been clear that we’re not going to be limited by geography,” State Department spokeswoman Jen Psaki said. She described a range of actions being considered against the Islamic State, and noted that decisions and discussions were ongoing.

Over the past day, Secretary of State John Kerry and other administration officials have reached out to leaders from Australia, the UAE, Jordan, Qatar, Saudi Arabia, Italy and Israel to discuss how to combat the Islamic State. Psaki said the discussions focused on what each country might contribute — including weapons, humanitarian aid and other resources — and noted that some nations already have.

Obama “wants to build an international coalition,” Psaki said. “That’s not going to be overnight. We need capabilities from many countries.”

During a press conference in Estonia on Wednesday, Obama said the U.S. is looking to “degrade and destroy” ISIS.

“Our objective is clear, and that is to degrade and destroy ISIL so that it’s no longer a threat,” Obama said, using an alternate acronym for the Islamic State.

Obama vowed the U.S. would not forget the “terrible crime” against Foley and Sotloff.

“We will not be intimidated. Their horrific acts only unite us as a country and stiffen our resolve to take the fight against these terrorists,” Obama said. “And those who make the mistake of harming Americans will learn that we will not forget, and that our reach is long and that justice will be served.”

Obama also sought to clean up the damage from his statement last week that “we don’t have a strategy yet” for dealing with ISIS in Syria.

“It is very important from my perspective that when we send our pilots in to do a job, that we know that this is a mission that’s going to work, that we’re very clear on what our objectives are, what our targets are,” Obama said. “We’ve made the case to Congress and we’ve made the case to the American people, and we’ve got allies behind us so that it’s not just a one-off, but it’s something that over time is going to be effective.”

Separately, during an appearance in Maine, Vice President Joe Biden declared that the U.S. will pursue the militants to “the gates of hell.”

“As a nation, we’re united. And when people harm Americans, we don’t retreat, we don’t’ forget,” Biden said. “We take care of those who’re grieving and when that’s finished they should know we will follow them to the gates of hell until they are brought to justice. Because hell is where they’ll reside.”

In the Sotloff video, a masked militant warns Obama that as long as U.S. airstrikes against the Islamic State group continue, “our knife will continue to strike the necks of your people.”

“I’m back, Obama, and I’m back because of your arrogant foreign policy towards the Islamic State, because of your insistence on continuing your bombings … and on Mosul Dam, despite our serious warnings,” the executioner said. “You, Obama, have but to gain from your actions but another American citizen. So just as your missiles continue to strike out people, our knife will continue to strike the necks of your people.”

Obama responded that the airstrikes have been effective in blunting the militant threat and he will continue to battle the “barbaric and ultimately empty vision” that the Islamic State represents. He said he will consult with NATO allies at a summit in Wales Thursday and Friday on a strategy to combat the Islamic State and other militant networks that arise.

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