A temporary agreement with Iran to allow United Nations inspectors continued access to the country’s atomic facilities lays the groundwork for the return to full verification measures if and when Tehran allows it, the head of the International Atomic Energy Agency said Monday.

Iran began restricting international inspections last week, but under a last-minute deal worked out during a trip to Tehran by Rafael Grossi, the head of the Vienna-based UN atomic watchdog, some access was preserved.

Under the agreement, Iran will no longer share surveillance footage of its nuclear facilities with the IAEA but it has promised to preserve the tapes for three months. It will then hand them over to the IAEA if it is granted sanctions relief. Otherwise, Iran has vowed to erase the tapes, narrowing the window for a diplomatic breakthrough. Inspections are a critical part of the landmark 2015 nuclear deal with world powers, known as the Joint Comprehensive Plan of Action, or JCPOA.

Since President Donald Trump pulled the US unilaterally out of the deal in 2018, Iran has been slowly increasing its violation of the pact by enriching more uranium than allowed, and to a greater purity than allowed, among other things.

The violations have been intended to put pressure on the other signatories to the deal — Britain, France, Germany, Russia and China — to come up with ways to offset the economic devastation caused by American sanctions, but so far they have not been able to come up with a solution suitable to Iran.

US President Joe Biden has said he is ready to join talks with Iran and world powers to discuss a return to the deal. The new restrictions on inspections complicate matters, and, in effect, set the clock ticking on coming up with some sort of a resolution.