Hillary Clinton says that defeating the Islamic State terror network is a pillar of her national security program that she would achieve largely by extending and amplifying policies put in place by President Obama.

Donald Trump says his plan to confront the terror syndicate is to throw out that strategy because it failed.

“We’ve tried it President Obama’s way. Doesn’t work,” Trump said Monday, calling the administration’s approach, which Clinton helped carry out as secretary of state, weak and bungling. “He gave the world his apology tour,” Trump said of Obama. “We got ISIS and many other problems in return.”

Both candidates scrapped their planned campaign speeches Monday and focused instead on the mass shooting at a gay nightclub in Orlando over the weekend — the worst mass shooting in U.S. history and the worst terrorist attack on U.S. soil since Sept. 11, 2001. It was the first time their plans to deal with terrorism — again a central issue for voters in a presidential election — were set in direct comparison.

“We cannot contain this threat. We must defeat it,” Clinton said before lacing a discussion of her plan with an appeal to reject hatred and division in politics and to unite as a nation in the spirit of solidarity that followed the 9/11 attacks.

Speaking in Cleveland, Ohio, Democratic presidential candidate Hillary Clinton called for unity in the wake of the tragic shooting in Orlando. Here are key moments from that speech. (Reuters/Associated Press)

The presumptive Democratic nominee’s program is detailed and long, drawing on Clinton’s résumé as a New York senator and secretary of state.

On Monday, she homed in on the hardest counterterrorism question raised by the Florida attack — how to deal with Americans who are recruited or inspired by terrorism and face no hurdles such as overseas travel or difficulty buying weapons.

“The threat is metastasizing. We saw this in Paris. And we saw it in Brussels. We face a twisted ideology and poisoned psychology that inspires the so-called lone wolves, radicalized individuals who may or may not have contact and direction from any formal organization,” she said Monday.

Trump, in contrast, has put forward a plan to defeat the Islamic State and protect Americans from terrorists rooted in big general ideas rather than granular details. Much of his policy has been advanced through tweets and sometimes with what appear to be off-the-cuff remarks.

In his Monday speech, Trump argued that the country’s homegrown terrorism problem is fundamentally an immigration problem.

“The bottom line is that the only reason the killer was in America in the first place was because we allowed his family to come here,” said Trump, speaking of the Orlando shooter.

Republican presidential candidate Donald Trump speaks at Saint Anselm College on June 13 in Manchester, N.H. (Jim Cole/AP)

Clinton would combine military action, diplomacy and law enforcement with a crackdown on international financing for terrorism, efforts to stem the flow of foreign fighters to and from the Islamic State battlefield and counter radicalization and recruitment online — a vexing problem that her State Department struggled with little success to address. She also would expand efforts to identify potential terrorist recruits and monitor and interrupt terrorist communications.

Clinton’s campaign website promises to confront the Islamic State “in a way that builds greater stability across the region, without miring our troops in another misguided ground war.”

She would intensify the current coalition military air campaign, which she claimed Monday has scored some recent successes, and expand U.S. and allied support for local forces on the ground. Although she has previously broken with the Obama White House to favor a militarily enforced “no-fly” zone to protect civilians in northern Syria, she has not raised the issue lately.

She would press diplomacy to end Syria’s civil war and the renewed sectarian conflict in Iraq, both of which helped allow the growth and expansion of the terror group also known by the acronyms ISIL and ISIS.

Trump’s signature proposal to safeguard the homeland is a temporary ban on most foreign Muslims entering the country. Trump also said he would “suspend immigration from areas of the world where there is a proven history of terrorism against the United States, Europe or our allies, until we fully understand how to end these threats.”

Trump, perhaps in reaction to criticism and confusion over what he meant, later tweeted: “In my speech on protecting America I spoke about a temporary ban, which includes suspending immigration from nations tied to Islamic terror.”

It is still not clear whether the wording he used Monday would apply to those who are natives of or were traveling through predominantly Muslim countries.

Trump first proposed the ban days after the last mass shooting, in San Bernardino, Calif., in December.

At the time, he released a statement endorsing a “total and complete shutdown of Muslims entering the United States until our country’s representatives can figure out what is going on.”

Although Clinton and many Republicans reacted with revulsion, the ban has remained a central Trump tenet and a reason many supporters cite for backing him.

“What has happened in Orlando is just the beginning. Our leadership is weak and ineffective. I called it and asked for the ban. Must be tough,” he tweeted Sunday.

“We have to screen applicants to know whether they are affiliated with or supporting radical groups and beliefs,” Trump said. “We have to control the amount of future immigration in this country, and we have to prevent large pockets of radicalization from forming inside America.”

The Republican inaccurately stated that “hundreds of thousands” of Muslim immigrants are entering the United States without screening.

He also seemed to suggest that the Orlando killer, Omar Mateen, had been born in Afghanistan, deviating from his script. Trump’s prepared remarks said he was “born to Afghan parents who immigrated to the United States.” Mateen was born in the United States to Afghan immigrants.

Trump has urged Muslims in the United States to be more vigilant about reporting suspicious activity. He has also called for “surveillance of certain mosques.”

“We have, right now, thousands of people in the United States, living in the United States who have the same kind of hate in their heart as he had,” Trump said Monday on CNN. “And we have to know who they are.”

Trump has also called for a wall to be built along the United States-Mexico border, which he has said over and over will be paid for by Mexico. Trump also wants to deport the millions of undocumented immigrants living in the United States.