Hillary Clinton backed the establishment of safe zones in Syria, along with efforts to investigate Russia for war crimes committed in support of President Bashar al-Assad in the second US presidential debate with Donald Trump.
Meanwhile, tax policy, healthcare, and US Supreme Court appointments were also on the agenda.
Mrs Clinton said she supported efforts to probe "war crimes committed by the Syrians and the Russians and try to hold them accountable."
She said there is a determined effort by the Russian air force to destroy Aleppo.
She also accused Russia of trying to tilt the presidential election in Mr Trump's favour with a series of email hacks.
In response, Mr Trump appeared to reject findings from the intelligence community that Russia was behind the hacks, saying "maybe there is no hacking."
Mr Trump denied having loans with Russia and repeated his promise to release his tax returns as soon as an audit is completed.
Responding to Mrs Clinton's claim that Mr Trump had praised Russian president Vladimir Putin, Mr Trump said: "I don't know Putin. I think it would be great if we could get along with Russia because we could fight Isis together as an example.
"I know nothing about Russia. I know about Russia but I don't know anything about the inner workings of Russia."
Tax policy
Mrs Clinton said her Republican rival was living in an alternative reality and his tax plan would give the wealthy and corporations the biggest tax cut they have ever had.
Mr Trump said Mrs Clinton was "all talk, no action" with her tax plan.
On his personal tax affairs, Mr Trump acknowledged he used his losses to avoid paying taxes; "of course I do" he said.
He said he had a write-off and a lot of it was depreciation, "I love depreciation" he said.
Obamacare 'will implode' in 2017
Mr Trump said Obamacare is a disaster and will implode in 2017. He said it needs to be replaced with something much less expensive.
Unless you get hit by a truck, you are never going to be able to use Obamacare because deductibles so high, Mr Trump said.
The whole thing "is a fraud", the Republican candidate stated.
Supreme Court appointments addressed
The candidates were asked what kind of judges they would like to see appointed to the US Supreme Court and Mrs Clinton said she would appoint justices who have real life experience.
She said she wants a Supreme Court that will support abortion rights and gay marriage.
Mr Trump said he is looking for Supreme Court judges "in the mold" of Justice Antonin Scalia who died earlier this year.
He said he has chosen 20 judges as possible candidates.
