TEHRAN (TicToc by Bloomberg) — Iran warned European nations on Monday that it would breach in 10 days the landmark 2015 nuclear agreement unless they take action to alleviate the pressure of tightening U.S. sanctions in the coming weeks.

The spokesman for Iran’s atomic energy agency, Behrouz Kamalvandi, said the country would exceed a cap on stockpiles of low-grade uranium on June 27 and threatened to raise enrichment purity beyond a 3.67% limit meant to prevent Iran from making weapons-grade material.

“This is an important test for Europe. It’s to their detriment that the U.S. is making decisions for them”, he said in a televised address from Arak heavy water plant. “Meetings and summits won’t suffice. Once they take actionable measures, we can return to our previous commitments.”

The announcement raises pressure on European nations who’ve urged Tehran to stick with a deal even after it was abandoned by the U.S. but have struggled to come up with a vehicle that would allow the Iranians to keep trading. It will also stoke further friction with the U.S., which has accused the Islamic Republic of being behind a spate of attacks on oil tankers near the Strait of Hormuz shipping chokepoint. Iran denies any wrongdoing.

After waiting a year for action, Iran threatened on May 8 to gradually withdraw from the accord unless the remaining parties throw it an economic lifeline within 60 days. It said it would no longer comply with a 300-kilogram cap on the storage of enriched uranium and a 130-ton limit on stocks of heavy water after the U.S. revoked key waivers that had allowed the Iranians to send excess heavy water to Oman and ship out surplus enriched uranium in exchange for natural, or yellowcake, uranium.