Donald Trump said Monday that Islamic terrorists are waging 'an absolute war' on America, and the U.S. needs more robust intelligence-gathering abilities – beginning with 'looking at the mosques' where some terrorists and would-be terrorists are radicalized.

'There's never been anything to this extent where we have people – we don't know who they are,' the Republican presidential nominee-in-waiting said on the 'Fox & Friends' program.

'It's absolute war, but we don't have uniforms,' he said, previewing a policy speech planned for New Hampshire in the afternoon.

Donald Trump phoned in to 'Fox & Friends' on Monday morning, hours before a planned policy speech that is expected to focus on fighting terrorism and attacking Hillary Clinton's perceived weaknesses.

Trump is in New Hampshire on Monday for his speech, following weekend rallies in Tampa and Pittsburgh

Police forensic investigators worked at the crime scene of Saturday night's mass shooting on Sunday as bodies were removed from the Pulse gay nightclub in Orlando, Florida

The United States, he said, should dramatically ramp up a domestic intelligence operation aimed at rooting out radicals in America's Muslim communities, including the houses of worship that sometimes double as terrorism organizing spaces.

'We have to be very strong in terms of looking at the mosques,' he said, while complaining that 'a lot of people say, "Oh, we don't want to do that, Oh, we don't want to do that".'

'We're beyond that,' Trump declared.

A lone gunman who swore allegiance to the ISIS terror army opened fire in a gay nightclub in Orlando, Florida on Saturday night, killing 49 people and wounding dozens of others.

'That man yesterday was sick with hate,' Trump said. 'You have many, many people, thousands of people already in our country that are sick with hate.'

'And people that are around, Muslims, know who they are largely. They know who they are. They have to turn them in.'

'We're not getting the right intelligence,' he said.

'We need a stronger intelligence community. And the only way we can do that in this case, having to do with radical Islamic terror, and that's the point. Obama won't do that because he doesn't want to single out this group.'

He spoke out against gun control, telling CNN's New Day: 'If people in that room had guns, with the bullets flying in the opposite direction right at, right at his head, you wouldn't have had the same tragedy that you ended up having.'

Trump also blasted Hillary Clinton, the Democrats' presumptive presidential nominee.

'She's a weak person. She is weak on so many different levels,' he said, describing her as 'almost like a maniac' on the basis of a forthcoming tell-all book by a former U.S. Secret Service officer.

'She is not the right person, especially in these times. These are times when you need solidity.'

Trump has been using Twitter to put pressure on President Obama and connect the weekend terror attack with his past calls for tougher action on radical Islamists

He said Clinton has refused to describe America's largest domestic security threat as 'radical Islamic terrorism' because she is carefully hewing to the Obama administration's position.

'She's just following his exact line. She won't utter the words either – radical Islam – she won't even utter the words. He won't utter the words!' he boomed.

Clinton is 'afraid to mention it because her boss will be angry at her ... and you know why that is.'

That was a veiled reference to claims he has made on the campaign trail before – that Clinton is reluctant to cross Obama publicly because the U.S. Justice Department holds her fate in its hands.

The former secretary of state faces a pair of criminal investigations.

One probe focuses on classified material found in thousands of emails she kept on a private server in her home while she was the government's top diplomat.

The other concerns claims that she sold her influence at the State Department in exchange for speaking fees for her husband and contributions to their family foundation.

Investigators worked the terror attack scene all weekend, removing bodies and collecting evidence

WATCH: Trump responds to questions about how his ban would have stopped shooter, who was born in the U.S. https://t.co/RpM3qLtQ2j — Good Morning America (@GMA) June 13, 2016

Pictured: Omar Mateen, 29, the suspected Islamic extremist who slaughtered at least 49 people in the Orlando terror attack

Trump reserved some of his toughest words for Obama.

'We're led by a man that either is not tough, not smart or he's got something else in mind,' he said on Monday. 'And the "something else in mind" – people can't believe it.'

'He doesn't get it.' Trump added. 'Or he gets it better than anybody understands. It's one or the other.'

Obama focused on gun control in a somber statement on Sunday afternoon, drawing outrage from conservatives who saw a president engaged in an opportunistic power grab.

He added on NBC's 'Today' show that 'there are a lot of people that think that maybe he doesn't want to get it.'

'A lot of people think that maybe he doesn't want to know about it. I happen to think that he just doesn't know what he's doing,' he said.

'Calling on another gun ban – I mean, this man has no clue,' Trump said on Fox.

'You have thousands of shooters like this with the same mentality out there in this country. And we're bringing thousands and thousands of them back into this country, and into the country every year. We're allowing them to come in.'

'I'm talking about people coming in from Syria, where we have no idea who they are,' he clarified. 'We have no idea as to paperwork, as to where they came from. This could be the all-time great Trojan horse.'

'I don't know how many people are going to end up dying from this, but [it's] no different than this maniac that just did this to us yesterday,' Trump said.

SNAPCHAT AUDIO CAPTURES SCREAMING HORROR AS GUNMAN FIRED 24 SHOTS IN JUST NINE SECONDS A Snapchat video captured the sound of 24 gunshots being fired in just nine seconds at Orlando's Pulse nightclub on Sunday morning. The footage obtained by WESH 2 News shows a dark street with police cars flashing in the distance. In the background, there is the sound of one assault rifle firing two or more shots a second, and a woman's scream. At the end of the video there is the sound of a gunshot from another gun. The person filming says: 'Oh... my god... People are getting shot dude...' A male voice next to him says: 'We need to get out of here.' But they stand there stunned as the gunshots keep going. 'This guy's firing out shots,' the friend adds. The harrowing footage offers a glimpse into the horror that unfolded in Florida between 2am and 5am this morning. Advertisement

.@realDonaldTrump: Hillary is a disaster! She is not fit to be President in times like these.https://t.co/LyqGIbLcVk — FOX & Friends (@foxandfriends) June 13, 2016

Later on ABC's 'Good Morning America,' Trump reiterated his call for 'a ban on people coming in from Syria, coming in from different parts of the world with this philosophy that it so hateful.'

That seemed to represent a refined position from a broader one – a blanket ban on the entry of all non-citizen Muslims – that drew national outrage in December.

'We have many people coming in whose hate is equal to his and just as bad and even worse, frankly,' he said, referring to the Orlando shooter.

But in a morning tweet, Trump pivoted back to his Muslim emigration ban, which he framed a month ago as just 'a suggestion.'

'What has happened in Orlando is just the beginning,' he wrote on Twitter.