Azerbaijan has released a shipment of Russian nuclear equipment destined for Iran after holding it for about a month.

Azerbaijani officials say the shipment passed Thursday through a customs checkpoint on the country's border with Iran.

Its release came after Russia provided information on the shipment earlier this week.

Azerbaijani customs officers stopped the Russian cargo from entering Iran on March 29, saying they wanted to make sure it did not violate U.N. sanctions against Tehran. Iran demanded that Azerbaijan release the cargo.

Russian officials say the shipment contains heat insulation material for a nuclear power plant that Russia is building in the Iranian city of Bushehr.

Meanwhile, Iran says it will hold another round of talks with the International Atomic Energy Agency (IAEA) on Tehran's nuclear program by the end of next week.

IAEA deputy director general Olli Heinonen has met Iranian officials in Tehran twice in the past two weeks. The U.N. agency said last week Iran had agreed to answer allegations that it conducted research on designing nuclear weapons.

On Friday, officials from Germany and the five permanent members of the U.N. Security Council, the U.S., Britain, France, Russia and China, will gather in London for talks on Iran's nuclear program.

The Security Council has imposed three sets of sanctions on Iran for its refusal to suspend uranium enrichment, a process that can be used to make nuclear weapons.

The United States and its Western allies accuse Iran of working to build a nuclear weapon. Iran says its atomic program is for peaceful purposes.

Some information for this report was provided by AFP and AP.