Clinton Says U.S. 'Disturbed' by Iranian, Hizbullah 'Activities' in Syria

U.S. Secretary of State Hillary Clinton accused on Thursday Iran and Hizbullah of playing an increasingly prominent role in the Syrian war.

The U.S. is "disturbed by increasing Iranian and Lebanese Hizbullah activities" in Syria, Clinton told reporters on the eve of her last day as secretary of state.

"I've done what was possible to do," she said.

But she painted a harrowing picture of a war that could still get worse.

"The worst kind of predictions about what could happen internally and spilling over the borders of Syria are certainly within the realm of the possible now," she said.

The conflict "is distressing on all fronts," Clinton said, a day before John Kerry is sworn in as her successor.

She pointed the finger primarily at Iran, accusing it of dispatching more personnel and better military materiel to President Bashar Assad's regime to help him defeat rebel forces.

She spoke after Syria threatened Thursday to retaliate for an Israeli airstrike, and its ally Iran warned ominously that the Jewish state would regret the attack.

In a letter to the U.N. secretary-general, Assad's regime stressed its "right to defend itself, its territory and sovereignty" and holding Israel and its supporters accountable. And Ali Abdul Karim Ali, Syria's ambassador to Lebanon, said his government maintained "the option and the capacity to surprise in retaliation."

In her strikingly candid assessment, Clinton spread the criticism to Russia, which has stymied U.S.-led efforts to set global sanctions against the Syrian regime at the U.N. Security Council.

"The Russians are not passive bystanders in their support for Assad. They have been much more active," she told reporters. "But maybe they will change. And maybe they will be more open to an international solution because they can't look at what's happening and not believe it could be incredibly dangerous to everyone's interests, including theirs."