WASHINGTON - The White House said on Tuesday that the potential deal between Iran and the UN nuclear watchdog on nuclear inspection is a "step forward," but it also stressed that the deal will be ultimately judged by Tehran's actions.

The White House statement came after Yukiya Amano, Director General of the International Atomic Energy Agency (IAEA), announced on Tuesday that an agreement on probing suspected work on Iran's controversial nuclear program was expected to be signed soon.  

"I think it's important to note that the announcement today is a step forward," White House spokesman Jay Carney told reporters at a briefing. "It's an agreement in principle. It represents a step in the right direction."

"But as we've said in the past about the totality of Iran's obligations and their fulfillment of them, we will make judgments about Iran's behavior based on actions, not just promises or agreements," he noted.

The potential agreement is meant to give the UN nuclear watchdog access to sites, scientists and documents it seeks to address international concerns over Iran's nuclear activities.

The IAEA announcement came just one day before the nuclear talks between Iran and the world's major powers, namely Britain, China, France, Russia, and the United States plus Germany, are due to start in Baghdad, the capital of Iraq.

Voicing skepticism about promises by Tehran, Carney said that Washington is "very clear-eyed" about Iranian behavior and vowed to continue to pressure the Islamic republic.

The United States will "continue to move forward with the sanctions that will be coming on line as the year progresses," he said.

"We expect those to have the kind of effect on Iran in terms of making it clear to the regime what the price of continued failure to meet its obligations will mean for that country and for its economy," Carney noted.