Israel told the U.S. military it planned to strike Hamas in advance, but didn’t provide a location or other specifics before launching its attack against a Hamas target in Qatar on Tuesday, a U.S. official tells ABC News.

The vague notification of a pending strike left the military to discern on its own that subsequent explosions in Qatar were the result of Israeli action.

The official declined to say when exactly the U.S. received the warning from Israel, noting only “it wasn’t sufficient enough to adequately warn regional partners.”

In an online post, Trump said that Special Envoy to the Middle East Steve Witkoff informed the Qataris of the Israeli action but “unfortunately, too late to stop the attack.”

Five members of Hamas and a member of Qatar’s Internal Security Force were killed Tuesday when Israel struck the headquarters of Hamas political leadership in Qatar’s capital city of Doha. Senior Hamas leadership were in the country to attend ceasefire talks, officials said.

According to Hamas, among those killed was the son of a senior Hamas leader Dr. Khalil Al-Hayya. Al-Hayya himself survived the strike, the group said.

The attack prompted a swift rebuke from Qatar, which called it a “flagrant violation of all international laws and norms.” Other key U.S. allies in the Gulf, Saudi Arabia and the United Arab Emirates, promised their support to Qatar.

Qatar, a wealthy nation that hosts one of the largest U.S. military bases in the region, has enjoyed warm relations with President Donald Trump. Earlier this year, the Gulf country gifted a luxury jet to use for presidential travel, which the Trump administration accepted with no conditions on what happens to the jet when Trump leaves office.

White House press secretary Karoline Leavitt told reporters on Tuesday that the U.S. military informed the Trump administration of the “impending” attack Tuesday morning before it took place, calling the bombing “unilateral” and saying the president spoke with Qatari officials.

“He assured them that such a thing will not happen again on their soil,” she said.

According to the Qatari government, officials there didn’t learn of the strike until explosions were already happening.