“We have confronted the Russians about stopping their continued arms shipments to Syria,” Mrs. Clinton said at an appearance with President Shimon Peres of Israel. “They have, from time to time, said that we shouldn’t worry; everything they’re shipping is unrelated to their actions internally. That’s patently untrue.”…

The fierce government assaults from the air are partly a response to improved tactics and weaponry among the opposition forces, which have recently received more powerful antitank missiles from Turkey, with the financial support of Saudi Arabia and Qatar, according to members of the Syrian National Council, the main opposition group in exile, and other activists.

The United States, these activists said, was consulted about these weapons transfers. Officials in Washington said the United States did not take part in arms shipments to the rebels, though they recognized that Syria’s neighbors would do so, and that it was important to ensure that weapons did not end up in the hands of Al Qaeda or other terrorist groups…

“The government of Syria lost some large chunks of territories and several cities to the opposition and wants to retake control of these areas,” Mr. Ladsous told reporters at the United Nations. “So now we have confirmed reports not only of the use of tanks and artillery, but also attack helicopters.”