Secretary of State Mike Pompeo on Sunday accused Iran of sowing “pure and blatant disinformation” about the downing of an unmanned U.S. drone last week.

Iran shot down the RQ-4A Global Hawk, a surveillance drone, Thursday morning. Iranian officials say the move was necessary because the drone entered Iranian territorial airspace. The United States has denied that claim.

In his remarks Sunday, Pompeo pushed back vociferously, accusing Iranian leaders of “selling” false information. Pompeo called the map tweeted by Iran’s foreign minister, which purported to show the drone’s path into Iranian airspace, “childlike” and said U.S. intelligence services “should leave no doubt in anyone’s mind about where that unarmed vehicle was.”

Pompeo also urged reporters to ignore Iran’s claims.

“We need to make sure that every news outlet, everyone who is observing this, understands what’s true and what the Iranian regime wants you to believe,” he said.

Pompeo spoke shortly before departing to Saudi Arabia and the United Arab Emirates, where he said he will work to build a “global coalition” against Iran.

And he reiterated that the United States is willing to negotiate with Iran with “no preconditions.”

Pompeo also promised even tighter sanctions on the country, saying a “significant set” of new economic conditions will be released Monday. He declined to offer specifics, but he noted that 80 percent of the country’s economy is already sanctioned.

“We are going to deny them the resources they need” to build a nuclear weapon, he said, “thereby keeping American interests and American people safe all around the world.”

Pompeo also confirmed that Trump sent North Korea’s Kim Jong Un a letter after South Korean news outlets reported that the message could set the stage for a third summit between the two leaders. He reiterated that the United States is still interested in meeting with Kim to discuss the country’s nuclear disarmament.

“We’re literally prepared to begin at a moment’s notice,” Pompeo said.