VIENNA Jan 17 (Reuters) - German Foreign Minister Frank-Walter Steinmeier said on Thursday a meeting of six big powers next Tuesday aimed to show international determination not to allow Iran to develop nuclear weapons technology.

Steinmeier was speaking to reporters before talks with International Atomic Energy Agency Director Mohamed ElBaradei.

"There are open questions which Iran urgently needs to resolve to reestablish lost trust. It remains the case that the international community cannot and will not permit nuclear weapons technology to be developed in this region," Steinmeier said.

"We will be meeting in Berlin in a few days time with the respective Security Council members to debate how we can express demonstrable unity on these questions in the future."

The West fears Tehran is secretly seeking an atom bomb. Iran says its nuclear programme is only for power generation and a recent U.S. intelligence estimate said Tehran had stopped an active nuclear arms drive in 2003, compounding disagreement within the six powers over next steps on Iran.

Steinmeier said he and ElBaradei were discussing possible solutions to the stand-off with Iran and emphasised that the findings of U.S. intelligence agencies were important and needed to be taken into account.

"Recently we have seen new estimates on the status of research and development work (in Iran)," he said. "In this connection it is of course important what the (U.S. National Intelligence Estimate) has expressed."

After their talks that lasted about an hour, neither Steinmeier nor ElBaradei made any further statement.

Germany said on Wednesday it wanted a new U.N. resolution increasing sanctions against Iran. Steinmeier and his counterparts from the five permanent members of the U.N. Security Council were expected to join the Berlin talks.

The U.N. nuclear watchdog chief had talks in Tehran last week to seek swifter cooperation with a long IAEA inquiry into Iran's nuclear history and an end to curbs on U.N. inspections meant to ensure its present programme is wholly peaceful.

ElBaradei came back with an agreement from Tehran to answer outstanding questions within a month about past, covert nuclear work that had military applications. (Reporting by Mark Heinrich, writing by Karin Strohecker; Editing by Charles Dick)