President Barack Obama accused critics on Tuesday of playing into the hands of Islamic State by comparing the fight against the militant group to World War Three, in an address aimed at laying out an optimistic vision of America's future.

Obama, who is delivering his last State of the Union speech to Congress before leaving office next year, said it was fiction to declare the United States was in economic decline or getting weaker on the international stage, despite rhetoric from Republican presidential candidates vying to replace him in the Nov. 8 election.

"Masses of fighters on the back of pickup trucks and twisted souls plotting in apartments or garages pose an enormous danger to civilians and must be stopped. But they do not threaten our national existence," Obama said, according to prepared remarks.

"That’s the story ISIL wants to tell; that’s the kind of propaganda they use to recruit. We don’t need to build them up to show that we’re serious, nor do we need to push away vital allies in this fight by echoing the lie that ISIL is representative of one of the world’s largest religions," he said, referring to Islamic State by an acronym.

The remarks were a repudiation of Republican criticism of his strategy against Islamic State and, not so subtly, of Republican front-runner Donald Trump's call to temporarily ban Muslims from entering the United States.

Obama's address comes as 10 sailors aboard two U.S. Navy boats were taken into Iranian custody. Iran told the United States the crew members would be "promptly" returned, U.S. officials said. The event gave Republicans further fodder to criticize Obama's nuclear deal with Tehran.

Obama did not address the issue at the top of his speech.

The address is one of Obama's few remaining chances to capture the attention of millions of Americans before November's election of a new president who will take office next January.

South Carolina Governor Nikki Haley, who is delivering the Republican Party’s response to Obama’s address, will knock his record on fiscal and foreign policy while delivering a not-so-subtle jab at Republican presidential candidates such as Trump.

“During anxious times, it can be tempting to follow the siren call of the angriest voices. We must resist that temptation. No one who is willing to work hard, abide by our laws, and love our traditions should ever feel unwelcome in this country," she will say, according to excerpts of her remarks.

Haley is the daughter of Indian immigrants.

Obama stuck to themes he hopes will define his legacy.

He emphasized areas where compromise was possible with Republicans in Congress including criminal justice reform, trade and poverty reduction.

He called for lawmakers to ratify a Pacific trade pact, advance tighter gun laws and lift an embargo on Cuba.