Iran began its retaliation campaign early Friday, after warning Israel it would pay a “heavy price” for its attack.

Iran’s Defense Minister has warned that the country would strike U.S. military bases in the region if a conflict with the United States were to break out, as Donald Trump admitted he is now less confident that a nuclear deal can be reached.

Israel is continuing to strike Iran, after blasting its huge underground nuclear site and killing military commanders and nuclear scientists.

Another US official said that there was no change in operations at the Al Udeid Air Base in Qatar, the largest US military base in the Middle East, and that no evacuation order had been issued for employees or families linked to the US Embassy in Qatar, which was operating as usual.

If nuclear negotiations fail and conflict arises with the United States, Iran will strike American bases in the region, Defence Minister Aziz Nasirzadeh said on Wednesday, days ahead of a planned sixth round of Iran-U.

A United Nations conference co-hosted by France and Saudi Arabia aimed at forging a roadmap towards a two-state solution between Israel and the Palestinians has been postponed after Israel launched a military attack on Iran,

Israel’s attacks across Iran killed top military commanders and targeted military sites. Israel vowed to continue strikes until it meets its objectives.