Washington: Republican presidential candidate Donald Trump on Sunday said he has no relationship with Russian President Vladimir Putin as being alleged by his opponents.

"I have no relationship with him (Putin)," Trump said, adding that he had praised him the in the past because he had said some nice things about him.

His comments came amid scrutiny of the Republican presidential nominee following the leak of nearly 20,000 Democratic National Committee (DNC) emails.

"He said very nice things about me, but I have no relationship with him. I don't -- I've never met him," Trump said.

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"I mean he treats me... with great respect. I have no relationship with Putin. I don't think I've ever met him. I never met him. I don't think I've ever met him," Trump reiterated.

The real estate mogul said he has never spoken to Putin on the phone. "When we had the Miss Universe contest a number of years ago, we had Miss Universe in Moscow, in the Moscow area, he was invited. He wanted to come. He wasn't able to come. That would have been a time when I would have met him," he said.

However, Trump insisted that there is nothing wrong in having a good relationship with Russia. "If our country got along with Russia, that would be a great thing....But if we can have a good relationship with Russia and if Russia would help us get rid of ISIS, frankly, as far as I'm concerned, you're talking about tremendous amounts of money and lives and everything else, that would be a positive thing, not a negative thing," Trump said.

He also attacked his Democratic rival Hillary Clinton, calling her a dishonest person with a bad temperament. "She's a very dishonest person. I have one of the great temperaments. I have a winning temperament. She has a bad temperament. She's weak. We need a strong temperament and that's all it is, I have a strong temperament," Trump told ABC News in an interview.

Read: Trump accuses Clinton of rigging upcoming Presidential debates

Appearing on a Sunday talk show, Trump claimed that he is leading in polls and is headed to win general elections in November.

"I think I have a great temperament. I beat 16 very talented people in and I've never done this before. You don't do that with a bad temperament. I'm leading her in the polls," he said and alleged that Clinton She doesn't know how to win.

"She's not a winner. She doesn't know how to win...I had a flawless campaign...She could barely beat Bernie," he said.

Meanwhile Trump campaign alleged that Clinton wants a low audience for the three presidential debates, with Trump questioning the need to have the much-anticipated debates on a days of popular NFL games.

The three presidential debates scheduled are on September 26 at Hofstra University, Hempstead in New York, October 9, Washington University in St Louis, St Louis Missouri and University of Nevada, Las Vegas, Nevada. The sole vice presidential debate would be held at Longwood University, Farmville in Virginia.

In a series of tweets, Trump said that two of these debates were being deliberately scheduled on a day having NFL games, which would attract low audience.