Trump says damage to Iran's nuclear sites is 'far below ground level'

ABC News' Mary Bruce asked Leavitt to clarify the president's statement that he would make a decision within the next two weeks.

"Is he saying that if Iran does not come back to the negotiating table within the next two weeks, that the president will strike?" she asked.

"The president is saying that he will make a decision whether or not to go within the next two weeks. It's very clear and direct," Leavitt said.

Bruce followed up asking if the president is seeing any hope for negotiations.

"That's why he said in the statement that I just read for all of you, based on the fact that there's a substantial chance of negotiations that may or may not take place with Iran in the near future, he will make that decision within the next few weeks," Leavitt said.

American Airlines has suspended flights to Doha, Qatar, and United Airlines has suspended its daily flight to Dubai, United Arab Emirates, as they continue to monitor developments in the Middle East.

"Due to conflict in the region, United’s daily flights between Newark and Dubai (DXB) are paused," United Airlines said in a statement Thursday.

-ABC News' Ayesha Ali

White House press secretary Karoline Leavitt, at the top of her briefing on Thursday, shared a message from President Trump regarding the Israel-Iran conflict.

"I know there has been a lot of speculation amongst all you in the media regarding the president's decision making and regarding whether or not the United States will be directly," Leavitt said.

"I have a message directly from the president: 'Based on the fact that there's a substantial chance of negotiations that may or may not take place with Iran in the near future, I will make my decision whether or not to go within the next two weeks,'" Leavitt said, adding that's a direct quote from Trump.

Israeli President Isaac Herzog told ABC News that Israel can win the war against Iran without the U.S., but said that removing Iran's nuclear threat serves the "free world," including the U.S.

Asked what he would say to President Donald Trump, Herzog said, "I trust his judgement and I'm sure he'll make the right decision."

Herzog said it has only been a week since the war began and suggested the threat of Iran will not go away "instantaneously."

"Victory looks like removing the Iranian nuclear threat," Herzog said.

"The ayatollah is the head of the snake. He's been leading this operation. He's been speaking about eliminating my nation, my people, my family for decades. So clearly, he is a major, major objective of dealing with. But, I cannot say that the ayatollah is a part of our war objectives," Herzog told ABC News.

-ABC News' Ian Pannell