( CNN ) -- Vice President Joe Biden on Wednesday issued a sharp warning to ISIS militants , saying after the United States is done grieving the death of two American journalists , their killers will have to answer for their actions . `` They should know we will follow them to the gates of hell until they are brought to justice , '' he forcefully told an audience at an event on the New Hampshire-Maine border . `` Because hell is where they will reside . Hell is where they will reside . '' Biden opened his remarks in memory of Steven Sotloff , the journalist who was beheaded by ISIS militants Tuesday , two weeks after James Foley was executed in the same horrific manner on video . Foley was from New Hampshire , while Sotloff lived there for boarding school . ISIS video shows beheading of American journalist . Describing the perpetrators as `` barbarians , '' Biden vowed that Americans would not be frightened or intimidated by the heinous acts . `` We came back after 9/11 . We dusted ourselves off and we made sure that Osama bin Laden would never , ever again threaten the American people , '' Biden said . `` We came back Boston strong , blaming no one but resolve to be certain that this did n't happen again . '' `` As a nation , we 're united , and when people harm Americans , we do n't retreat , '' he later said . `` We do n't forget . '' ISIS executions heighten fears for Western hostages . The vice president , who 's mulling a 2016 presidential bid , made his remarks at the Portsmouth Naval Yard in a speech about the economy . He was accompanied on stage by U.S. Sen. Jeanne Shaheen , a New Hampshire Democrat who 's running for re-election this year . Previewing Biden 's trip , the campaign for former Republican Sen. Scott Brown , who 's challenging Shaheen for her seat in this year 's midterms , released a Web video that shows footage of the vice president supporting President Barack Obama 's foreign policy , an agenda the Brown campaign labels a `` failure . '' 'Degrade and destroy ' After Sotloff 's killing , Obama faced a chorus of bipartisan calls from Congress to act more aggressively and come up with a concrete strategy to combat ISIS , beyond the already ongoing targeted air strikes . Speaking Wednesday , Obama addressed his much criticized statement last week that he has no strategy on ISIS . He said he was referring to a military strategy in Syria that `` might '' require congressional approval . `` Our objective is clear . That is to degrade and destroy ( ISIS ) so it 's no longer a threat , '' he said . `` We can accomplish that . It 's going to take some time , it 's going to take some effort . '' Obama : U.S. wo n't back down to ISIS . The president said the world needs a regional strategy to defeat the group . `` We 've been putting together a strategy that was designed to do a number of things ... What we have to make sure is we have a regional strategy in place , '' he said .
Of the U.S. journalists ' killers , vice president says , `` We will follow them to the gates of hell '' `` Because hell is where they will reside , '' he added . The Vice President said that if a journalist were killed in Iraq or Afghanistan, it would be an act of war and not something for which there was any justification.