Iranian people burn the American flag as they mark the anniversary of the seizure of the US Embassy in Tehran, Nov. 4, 2018. Tasnim News Agency / Handout via Reuters.

Iran denied on Friday it had violated an international convention by not fully declaring its chemical weapons capabilities to the UN, describing a US allegation to that effect as groundless, state TV reported.

In a meeting of the Organisation for the Prohibition of Chemical Weapons in The Hague on Thursday, ambassador Kenneth Ward reiterated US concerns that Iran maintained a chemical weapons program that it has failed to declare to the agency.

“Once again America has leveled groundless accusations against Iran … which we strongly reject,” Foreign Ministry spokesman Bahram Qasemi was quoted as saying by Iranian TV.

Washington’s aim, Qasemi said, was to divert international attention from its continued support for Israeli chemical arsenals. Iran does not recognize Israel.

Israel neither confirms nor denies having weapons of mass destruction. It signed the Chemical Weapons Convention in 1993, but has yet to ratify it, saying that should be preceded by progress in Middle East peacemaking.

Tension has increased between Washington and Tehran since May, when President Donald Trump reimposed sanctions after pulling out of a 2015 nuclear deal, under which they had been lifted, between Iran and six major powers.