US President Donald Trump will decide whether or not to join Israel’s air campaign against Iran’s nuclear facilities within the next two weeks as he awaits the outcome of diplomatic efforts between Tehran and Washington, the White House said Thursday.

The announcement, read aloud by Press Secretary Karoline Leavitt, appeared to signal the administration’s latest U-turn over the question of whether to commit American forces believed vital to destroying Iran’s most hardened nuclear sites, after a week that saw him vacillate sharply between support for a peaceful solution and a threat to kill Ayatollah Ali Khamenei.

On Wednesday, he said nobody knew what he would do.

“Based on the fact that there is a chance for substantial negotiations that may or may not take place with Iran in the near future — I will make my decision on whether or not to go within the next two weeks,” Leavitt said at a White House press briefing.

She confirmed that negotiations were continuing to take place between the US and Iran on the nuclear issue despite Israel’s offensive, after a Reuters report revealed that Trump’s special envoy Steve Witkoff had held a number of phone calls with Iranian Foreign Minister Abbas Araghchi.

Leavitt said any deal would have to prohibit enrichment of uranium by Tehran and eliminate Iran’s ability to achieve a nuclear weapon.

“The president is always interested in a diplomatic solution … if there’s a chance for diplomacy, the president’s always going to grab it,” she said. “But he’s not afraid to use strength as well, I will add.”

Hours before she spoke, an Israeli official told The Times of Israel that Jerusalem believed Trump may decide within the next couple of days to join in strikes against the Islamic Republic.

“The expectation is that they join, but no one is pushing them,” said the official on Thursday. “They have to make their own decision.”

The two-week timeline would seem to put the prospect of American involvement beyond Israel’s war plans, with the Israel Defense Forces saying earlier this week it expects to complete its objectives of destroying Iran’s nuclear and ballistic programs within a week or two.

Netanyahu told Israel’s Kan broadcaster that the campaign was proceeding “ahead of schedule.”

He added that Israel could hit all nuclear facilities in Iran, including Fordo, without saying whether it would require US assistance.

“We will achieve all our objectives and hit all of their nuclear facilities. We have the capability to do that,” he said.

Whether Trump “wants to join or not — that’s entirely his decision,” Netanyahu added.

Critics say that in the five months since returning to office, Trump has issued a range of deadlines – including to warring Russia and Ukraine and to other countries in trade tariff negotiations – only to suspend those deadlines or allow them to slide.

“I think going to war with Iran is a terrible idea, but no one believes this ‘two weeks’ bit,” Democratic Senator Chris Murphy said on the social media platform X. “He’s used it a million times before to pretend he might be doing something he’s not. It just makes America look weak and silly.”

According to a CBS report Thursday, the US president was briefed earlier in the day on the pros and cons of bombing Iran’s subterranean Fordo enrichment facility, which is seen as a key target in dismantling Tehran’s nuclear program.

Trump has been weighing a strike on Fordo for several days now, according to reports. The site, buried deep underground in central Iran, is believed to be out of reach of Israeli aerial weaponry.

An American strike on the facility would presumably require the use of so-called “bunker-buster” bombs, which weigh 30,000 pounds each and are too heavy for Israel’s fleet of fighter jets.

Leavitt said Trump had been briefed on the Israeli operation on Thursday and remained in close communication with Prime Minister Benjamin Netanyahu. She said Iran was in “a deeply vulnerable position” and would face grave consequences if it did not agree to halt its work on a nuclear weapon.

Ahead of a scheduled intelligence briefing in the Situation Room around noon Thursday, CNN reported that Trump huddled with his national security team consisting of Vice President JD Vance, Defense Secretary Pete Hegseth, CIA Director John Ratcliffe and Witkoff.

The Situation Room location suggests the subject matter discussed at the briefing was more sensitive than the US president’s daily intelligence update held in the Oval Office, the outlet reported.

The Wall Street Journal reported Wednesday that the American president had approved attack plans on Iran the night prior, but held off on striking the country to give diplomacy a chance.

Trump denied the report, saying on Truth Social that the outlet has “No Idea what my thoughts are concerning Iran!”

Meanwhile, a key Iranian body warned any US intervention in support of its ally Israel would be met with a “harsh response” from the Islamic Republic.

“The criminal American government and its stupid president must know for sure that if they make a mistake and take action against Islamic Iran, they will face a harsh response from the Islamic Republic of Iran,” the Guardian Council said in a statement carried by state television.

The US has appeared to be gearing up in recent days for an Iranian attack on its forces abroad, as it evacuated several planes from its base in Qatar and moved US Navy ships formerly stationed in Bahrain, CNN reported.

Later Thursday, US carriers United Airlines and American Airlines announced they were canceling flights to the Middle East.

Earlier this week, non-sheltered American aircrafts — planes not housed in hangars — were moved out of al-Udeid air base in Qatar, an official confirmed to CNN. US Navy ships that had been deployed at an American base in Bahrain had also left port in recent days.

US Central Command has stocked up on additional supplies of blood in the region, standard procedure ahead when there is a perceived possibility of an attack on US forces overseas.

Israel says its sweeping assault on Iran’s top military leaders, nuclear scientists, uranium enrichment sites and ballistic missile program launched on June 13 is necessary to prevent the Islamic Republic from realizing its avowed plan to destroy the Jewish state.

Despite initially distancing itself from Israel’s military operation, the White House has since played up the idea that it has a role in the operation, without detailing what form the support has taken.

Arms are likely part of the backing.

Israel’s Defense Ministry announced Thursday that several cargo planes carrying armaments and military equipment for the IDF landed in Israel —with the vast majority of planes coming from the US.

The ministry said the delivery is “part of efforts to strengthen operational continuity and support all the IDF’s needs, both for achieving the goals of the war and for improving readiness and stockpiles.”

Since the start of Israel’s operation against Iran, 14 cargo planes with equipment for the IDF have landed in Israel, the ministry said.