German foreign minister at G7 meeting: Too early to reward Iran over nuclear talks

German Foreign Minister Frank-Walter Steinmeier smiles as he signs the Golden Book of the city of Luebeck prior to meeting of the G7 foreign ministers in Luebeck, northern Germany, Tuesday, April 14, 2015. The meeting is being held ahead of the G7 leaders summit in Germany from June 7 to 8, 2015. (AP Photo/Markus Schreiber, Pool) (The Associated Press)

German Foreign Minister Frank-Walter Steinmeier, second right, signs the Golden Book of the city of Luebeck prior to a meeting of the G7 foreign ministers in Luebeck, northern Germany, Tuesday, April 14, 2015. The meeting is being held ahead of the G7 leaders summit in Germany from June 7 to 8, 2015. (AP Photo/Markus Schreiber, Pool) (The Associated Press)

LUEBECK, Germany – Germany's foreign minister says it's too early to reward Iran for a preliminary agreement on its nuclear program, criticizing Russia's decision to lift a ban on delivery of an air defense missile system.

Frank-Walter Steinmeier spoke as he welcomed counterparts from the Group of Seven powers Tuesday to a meeting in northern Germany. They're expected to discuss Iran, Ukraine and Yemen among other issues.

Asked about the Russian decision, Steinmeier said negotiators are "in the middle of a process" of trying for a final deal with Iran. He said U.S. senators shouldn't try to obstruct further talks "unnecessarily" but "it is also too early to offer rewards."

There is a June 30 deadline for a deal. Steinmeier says that's when it will be possible to say how economic relations develop.