President Donald Trump's decision to order a cruise missile strike on a Syria-government airfield is evidence he is not colluding with Russia and will not be "pushed around" by President Vladimir Putin, Eric Trump told the U.K.'s Daily Telegraph on Tuesday.

The U.S. president's son stressed his father would not be intimated by Putin's hardline stance concerning the Syrian conflict and insisted his father would prove there is "no-one harder" should Moscow "cross us".