The United States has confirmed Turkey's claim that a Russian jet had violated Turkish airspace before being shot down."The available information, including evidence from Turkey and our own sources, indicates the Russian aircraft violated Turkish airspace," State Department spokeswoman Elizabeth Trudeau said Monday in Washington. "We also know that the Turks warned the Russian pilots multiple times before the airspace violation, to which the Turks received no response.""We support Turkey's right to defend its territorial airspace," Trudeau said. "But as the president has said, Secretary Kerry has said: It's important that the Russians and the Turks talk to each other at this point and take all measures to de-escalate the situation," she added.