U.S. and European diplomats are pleased with the progress that is being made in talks aimed at Iran's nuclear program.

A new round of negotiations is set for next month in Geneva.

After a group meeting and then a one-on-one session between Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif, Kerry called the talks "constructive" and said he was struck by a "very different tone" from Iran.

But Kerry said words are not enough and that action must be taken if Iran wants to proce it is not seeking to devlop nuclear weapons.