Russia's foreign minister on Saturday warned that any effort by the U.S. and its allies to impose a no-fly zone over Syria would violate international law.
Sergei Lavrov, speaking at a news conference in Moscow with his Italian counterpart, referred to "leaks from Western media" that U.S. F-16 fighters and Patriot missile in Jordan might be used in neighboring Syria to suppress government forces fighting insurgents there.
"You don't have to be a great expert to understand that this will violate international law," Lavrov said.
Moscow has long been a close ally of the Syrian regime and amid earlier talk of the possibility of a no-fly zone against President Bashar al-Assad's military, Russia pledged to deliver surface-to-air missiles and additional MiG-29 fighters to Damascus.
Lavrov also said Saturday that the evidence of Syrian chemical weapons use cited by the U.S. is not reliable and doesn't meet requirements of the Organization for the Prohibition of Chemical Weapons.
He said the organization specifies that samples taken from blood, urine and clothing can be considered reliable evidence only if supervised by organization experts from the time they are taken up to delivery to a laboratory, The Associated Press reports.
The White House this week said the U.S. would begin sending military support to the rebels after it was determined that the Syrian government used deadly sarin gas on its own people. The Wall Street Journal reported that a limited no-fly zone was among the options being actively considered.
NPR's Deborah Amos, reporting from Amman, Jordan, tells Weekend Edition Saturday that the Obama administration's plan to arm the rebels comes after the Assad regime made significant gains against rebels in the town of Qusair.
All eyes are now on Aleppo, Syria's economic capital, and "whether or not that city will fall to this combined assault by government forces and fighters from Hezbollah, the Iran-backed Shiite militia in Lebanon."
If it does, she says, "Assad will be in a very strong position in any peace talks — so strong that he might not go at all."
Deborah says meetings are taking place between Western officials and Salim Idriss, the commander of the Supreme Military Council, an umbrella group including the Free Syrian Army, about the logistics of weapons shipments.
Idriss, a moderate, is favored by Western and Arab governments allied against the Assad regime over more extreme elements in the insurgency, she says.
"He's a moderate. He's the one who will get those arms," Deborah says. "His rebels have been vetted by Western intelligence agencies. He's going to ask for more in those meetings. He needs to take out those helicopters, pierce those tanks, but he's not going to get everything he wants."
Update At 3:50 p.m. ET. Egypt Calls For 'No Hesitation' On No-Fly Zone
Reuters reports that in a speech to Sunni Muslim clerics in Cairo, Egyptian President Mohamed Mursi urged world powers not to hesitate to enforce a no-fly zone over Syria.
The Islamist Mursi told the audience that he had cut all ties to Damascus and demanded that the Iranian-backed Hezbollah, which has backed Assad's regime against rebels, must leave Syria, according to Reuters.
Update At 3:30 p.m. ET. U.S. Will Leave Fighters, Missiles In Jordan After Joint Exercise
A statement from the Department of Defense says Secretary Chuck Hagel "has approved a request from the Kingdom of Jordan for a detachment of F-16s and Patriot Missiles to remain in Jordan following the conclusion of the Eager Lion Exercise next week."
Update At 10 a.m. ET. Kerry: Chemical Weapons Use Jeopardizes Political Settlement
Reuters quotes Secretary of State John Kerry as saying Syria's use of chemical weapons "threatens to put a political settlement out of reach."
Meanwhile, the news agency also reports that 71 Syrian army officers, including six generals, have defected to Turkey.
Reuters quotes unnamed Turkish officials as the source of its report. It says the defection, for unknown reasons, is the largest mass desertion of senior officers from Assad's regime in months.