Sanctions over the nuclear program have hurt Iran's economy. However, Tehran insists its program is peaceful but many Western nations fear it masks a weapons program.
International Atomic Energy Agency director-general Yukiya Amano says Tuesday the IAEA cannot at this moment judge whether Iran is planning, or will gain a nuclear weapon.
Amano said IAEA monitors "do not see any effect" from the sanctions and noted that Iran is still producing enriched uranium at up to 5-20 percent at "a quite constant pace."
On Wednesday, the EU's foreign policy chief will host political directors from six world powers that have intermittently held talks with Iran.