Iran has not declared all its chemical weapons capabilities to the global chemical warfare watchdog in The Hague, in breach of international agreements, the U.S. ambassador to the organization said Thursday.

Ambassador Kenneth Ward told the Organization for the Prohibition of Chemical Weapons (OPCW) that Iran has failed to declare a production facility for the filling of aerial bombs and maintains a program to obtain banned toxic munitions.

“The United States has had long-standing concerns that Iran maintains a chemical-weapons program that it failed to declare to the OPCW,” Ward said.

“The United States is also concerned that Iran is pursuing central nervous system-acting chemicals for offensive purposes,” he added.

There was no immediate reaction from Iran to Ward’s remarks, which add to tensions with Washington over Iran’s nuclear program, terrorism and the war in Syria.

Ward said Iran had failed to declare the transfer of chemical weapons to Libya in the 1980s, even after Libya declared them to the OPCW in 2011.

He cited the discovery of chemical-filled artillery projectiles, mortars and aerial bombs of Iranian origin as proof that Iran did not fully disclose its capabilities.

Ward’s allegations come amid growing pressure on Iran from President Donald Trump, who has withdrawn from the 2015 Iran nuclear deal and introduced several rounds of unilateral U.S. sanctions.

In a separate development Thursday, the U.N. nuclear watchdog said Iran is implementing its side of the deal with major powers.

Germany, France and Britain have been trying to prevent a collapse of the deal, under which international sanctions against Tehran were lifted in exchange for strict limits being placed on Iran’s nuclear activities.

Based on reporting by Reuters and AFP.