Iran's parliament speaker said that a three-month monitoring agreement with the UN International Atomic Energy Agency has expired, so inspectors can no longer access images of nuclear sites, state media reported Sunday.

Why it matters: The remarks by Mohammad Bagher Qalibaf underline the "narrowing window for the U.S. and others" to strike a deal with Iran, which has been enriching uranium at levels much higher than the 3.7% agreed to in the 2015 nuclear deal, AP notes.

Driving the news: The IAEA and Iran reached an agreement in February that allowed UN inspectors to continue necessary verification and monitoring of the country's nuclear facilities for up to three months.

• "Regarding this, and based on the expiration of the three-month deadline, definitely the International Atomic Energy Agency will not have the right to access images from May 22," Qalibaf said.

The big picture: Iran stepped up its enrichment efforts by building centrifuges and enriching nuclear materials to levels that violated the deal after former President Trump withdrew the U.S. from the international agreement in 2018.

What to watch: IAEA head Rafael Grossi, who's been in talks with Iranian officials to extend the monitoring deal, was due to hold a news conference on Sunday afternoon, Reuters reports.

Go deeper: U.S. and Iran remain far apart as nuclear talks reach critical stage