Hillary Clinton spokesman to Donald Trump: 'Go f--- yourself'

A spokesman for Hillary Clinton's campaign tweeted a strongly worded message to Donald Trump during the second presidential debate on Sunday night.

"Hey, @realDonaldTrump - regarding your claim that Captain Khan would be alive if you were president," tweeted Jesse Lehrich, Clinton's foreign policy spokesman. "Go f--- yourself."

The Republican presidential nominee had said during the debate that US soldier Humayun Khan would still be alive today because he wouldn't have approved the war in Iraq.

Khan died during the war and Trump landed in hot water earlier in the election cycle for criticizing Khan's parents.

Lehrich later apologized for his earlier tweet.

"I want to apologize for the clearly inappropriate nature and language of this personal tweet," he tweeted. "Sorry all."