Hillary Clinton

The revelations threatened to put the controversy over Trump's refusal to follow recent precedent and release his tax returns at the center of the presidential campaign less than 40 days before the election, after a week in which the Republican nominee has struggled to bounce back from a debate in which most analysts and scientifically conducted polls scored Clinton as the winner.

Clinton said she felt dizzy and lost her balance Sunday, but did not lose consciousness, and is now "feeling so much better."

"I was supposed to rest five days -- that's what they told me on Friday -- and I didn't follow that very wise advice," Clinton told CNN's Anderson Cooper in a phone interview.

"So I just want to get this over and done with and get back on the trail as soon as possible," she said.

The forum offered a preview of how the two candidates will present themselves to the country when they appear on stage September 26 at the crucial first presidential debate. The gulf between them was especially apparent when the discussion centered on Russia and combating ISIS.

Clinton has repeatedly slammed Trump on the campaign trail for his embrace of Russian President Vladimir Putin. But at the "Commander in Chief" forum hosted by NBC News, Trump once again praised the Russian leader in comparison to President Barack Obama.

So began the homestretch to Election Day, as both candidates on Tuesday put national security squarely at the center of the 2016 campaign in the belief that it gives them the advantage.

Trump began by unveiling a list of 88 retired military leaders endorsing his candidacy, including four four-star generals and 14 three-star flag officers.

Then, alongside retired Lt. Gen. Michael Flynn at an event in Virginia Beach -- where fighter jets could be heard whooshing overhead -- Trump said of Clinton that "virtually every decision she's made has been a loser."

Ms Abedin's announcement comes after a report emerged that he had allegedly exchanged sexual photos with a woman.

He appeared to have sent a photo of himself in his underpants with his toddler son nearby.

The former congressman resigned in 2011 after sending explicit photos to women by text message.

"After long and painful consideration and work on my marriage, I have made the decision to separate from my husband," Ms Abedin said in a statement.

The Democratic presidential candidate paid an effective federal tax rate of 34.2% last year.

Her running mate Tim Kaine, along with his wife Anne Holton, paid a rate of 20.3%, his returns show.

Mr Trump, a hotel developer with a fortune estimated to be in the billions, has refused to release his.

Presidential candidates typically release their tax returns to the media to show their effective tax rate, charitable donations and other financial details.

Judicial Watch, a conservative watchdog group, released 296 pages of emails from the Democratic presidential nominee, including 44 that Judicial Watch says were not previously handed over to the State Department by Clinton. The emails, many of which are heavily redacted, raise questions about the Clinton Foundation's influence on the State Department and its relations during her tenure.

He said that Mrs Clinton would put liberal justices on the Supreme Court if she wins the presidency in November, threatening gun ownership rights.

Speaking at a rally in North Carolina, Mr Trump hinted that gun rights advocates could stop her taking power.

That sparked an online backlash, many accusing him of inciting violence.

He replied that he was only urging gun rights supporters to vote in large numbers.

The remarks that sparked the firestorm were made at a rally in Wilmington on Tuesday afternoon.

Most forthright is New York's Daily News, which declares "Trump must go". "Hinting at assassination is too much, even for him," it explains.

Speaking at a rally in Des Moines, Iowa, Mrs Clinton said "words can have tremendous consequences."

Mr Trump sparked backlash after suggesting "Second Amendment people," or gun owners, could take action against her.

Mrs Clinton also said Mr Trump did not have the temperament to be president.

The former secretary of state called out Mr Trump for his recent row with the family of a fallen American Muslim soldier, which the military refers to as a Gold Star family.