Putin a better leader than Obama, says Trump

Donald Trump and Hillary Clinton faced off in a television forum hosted by US army veterans in New York on Wednesday, with the Republican nominee heaping further praise on Russian President Vladimir Putin, saying he is "far more of a leader" than current White House occupant Barack Obama.

The two candidates for the US presidential election in November appeared in one of the first joint televised events to discuss foreign policy.

The event was coordinated by NBC News and Iraq and Afghanistan Veterans of America, and was earmarked as preparation for the first official TV debate in three weeks' time.

Trump continued his recent praise of Putin, repeatedly referring to a potential improvement in relations with Russia if he were to become President.

"I think I would have a very, very good relationship with Putin and a very good relationship with Russia," he said.

"The man has very strong control over a country. It's a very different system and I don't happen to like the system, but certainly in that system he's been a leader, far more of a leader than our president has been."

Clinton vowed not to commit any more troops to Iraq and said that the US would not put any ground troops in Syria, if she were to be elected. The Republican nominee disagreed on the point, reiterating his belief that the surfacing of groups like Islamic State would not have happened "if we would have taken the oil".

The first female nominee for the White House was pressured on her record as Secretary of State, particularly her role in the private email scandal and her foreign policy decisions.

On her emails, Clinton said she "had made no excuses for it. It was something that should not have been done".

New polls on the race for the White House show Trump with a lead over Clinton, but many experts have backed the former Secretary of State, describing Trump as too unpredictable to gain the responsibilities associated with the role of commander-in-chief.