Meeting comes as European parties to pact weigh triggering mechanism that could lead to reimposition of sanctions over Iranian violations

After UK, France, and Germany warn UN chief about Iranian delivery systems, foreign minister says now is 'decisive moment'; Gantz calls for increased sanctions on Tehran regime

Prime minister said set to meet US Secretary of State Mike Pompeo, Germany's Merkel, and France's Macron, as they gather for summit of military alliance in UK capital

With radioactive material found at location said to be the compound Israel brought to world attention, IAEA says it is 'essential' that Tehran help resolve matter

Tehran informed IAEA its heavy water production surpassed 130 metric tons allowed by 2015 accord with world powers

Secretary of State Mike Pompeo says Tehran has no reason to restart enrichment at once-secret Fordo facility, but critics note allowances had given rare window into site

In leaked report, IAEA says Tehran informed it this week that its stock of heavy water had exceeded 130 metric tons

In AP interview, Abbas Ali Kadkhodaei, a member of the Guardian Council controlling all parliamentary legislation, says pulling out of 2015 pact would 'punish' the US

Kingdom berates Tehran after IAEA says uranium traces found at undeclared site, confirms enrichment at Fordo

Blasting Trump administration's withdrawal from 2015 pact, Rouhani says no one can blame his country for reducing its commitments to the treaty