World powers are seeking more consensus with Iran at the Baghdad talks after Teheran agreed "in principle" to permit nuclear watchdog inspectors to investigate a key site.

Representatives of the five permanent members of the UN Security Council, plus Germany, arrived in the Iraqi capital, Baghdad, on Wednesday for the two-day talks.

The main concern of the meeting is Iran's production of uranium enriched to 20 percent, which is far higher than needed for regular energy-producing reactors. Iran says it needs it for medical research.