PARIS — The head of the U.N.'s nuclear watchdog says he has no evidence that international sanctions against Iran have had any impact on its nuclear program.

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 European Union's foreign policy chief will host political directors from six world powers that have intermittently held talks with Iran.