Trump warns Iran after 'sneak attack' plan claim

President Donald Trump sent a stark warning to Iran on Wednesday during a White House briefing, hours after he accused the country of planning a "sneak attack" on US military troops in Iraq.

"If something bad happens, it's going to be very painful for the other side," Trump said, after being asked troops in Iraq were taking precautions.

Trump tweeted earlier Wednesday: "Upon information and belief, Iran or its proxies are planning a sneak attack on U.S. troops and/or assets in Iraq. If this happens, Iran will pay a very heavy price, indeed!"

Trump defended his decision to post the information on Twitter, saying, "I'm just giving them a warning. It's not a heads up."

Trump did not disclose additional information about what he was referring to.