U.S. Secretary of State John Kerry has toughened his stance on the fate of Syria's president, saying Bashar al-Assad cannot be part of a transitional government that would try to lead the country out of its civil war.
Kerry made the comment Thursday in Rome at a joint news conference with Jordanian Foreign Minister Nasser Judeh.
"The foreign minister will work with us, as they have, to try to bring all the parties to the table so that we can effect a transition government by mutual consent of both sides, which clearly means that, in our judgment, President Assad will not be a component of that transitional government,'' Kerry said.
The statement appears to clarify the U.S. position.
On Tuesday, Kerry said it is "impossible" for him as an "individual" to see President Assad governing Syria in the future, but he added that the Syrian president's fate is not for him to decide.
That comment came in a Moscow meeting with the foreign minister of Russia, which has insisted that only Syrians should determine the future of Assad, a longtime Russian ally.
In his Rome remarks on Thursday, Kerry also announced an additional $100 million in U.S. humanitarian aid for the Syrian people. He said the aid includes $43 million to help Jordan deal with the influx of more than half a million Syrian refugees from the two-year conflict.
Jordanian Foreign Minister Judeh said Amman appreciates the assistance. He said Syrian refugees constitute 10 percent of Jordan's population and warned the figure could rise to 40 percent by the middle of next year at the current rates of entry.
Kerry and Russian Foreign Minister Sergei Lavrov agreed this week to call an international conference later this month to press for peace talks between the Syrian government and rebels fighting to oust Assad.
The talks would be based on a June 2012 Geneva peace plan backed by major powers. It calls for the formation of a transitional government leading to elections, but does not specify Assad's political future.
U.N. Deputy Secretary-General Jan Eliasson said Thursday the joint U.N.-Arab League envoy for Syria Lakhdar Brahimi has agreed to stay on in the post in response to the U.S.-Russian initiative. Brahimi previously had expressed doubts about whether his diplomacy would achieve results.
Eliasson said U.N. Secretary-General Ban Ki-moon takes the U.S.-Russian announcement "very seriously" and will try to mobilize everyone to pursue a political rather than military solution in Syria.
The Syrian foreign ministry said it welcomes what it called the U.S.-Russian "rapprochement." It expressed confidence that Syrian ally Russia will maintain a "firm stance" against foreign interference in the internal affairs of any state.
But, Damascus said the credibility of U.S. support for a political solution depends on Washington working with its allies to stop "terrorism" - the term used by the Assad government to describe the rebellion.
Syria's main opposition coalition told VOA on Wednesday that any political solution to the civil war must begin with Assad and top security officials leaving power.
In an interview with VOA's Encounter program, Georgetown University security analyst Paul Pillar said Lavrov moved closer to the U.S. position by saying Russia is concerned about the Syrian people rather than any individual - an apparent reference to Assad.
"We are talking here about the prospect of a negotiated agreement in which Assad is not around as president. It would be a new political order in Syria, but one in which each of the confessional communities including the Alawites, including the Christians, as well as the majority Sunnis see themselves as having a role, and not simply having to fight to the death," said Pillar.
U.S. Senator Robert Menendez says if a political solution is not possible, he wants the Obama administration to have congressional support for arming Syrian rebels.
In an interview with VOA's sister television network Alhurra, Menendez said he is working on Senate legislation that would give President Barack Obama permission to provide shoulder-launched surface-to-air missiles, or MANPADS, to "thoroughly vetted" opposition elements.
"I think it may change the calculus of Russia and others if in fact the rebels can ultimately succeed in having military victories against Assad, and that would move us closer to an opportunity where a political solution can take place," Menendez said.
In an interview with Encounter, the head of the anti-Assad Syrian American Alliance Mahmoud Khattab said any supply of U.S. weapons to Syrian rebels also would send a message to the Syrian president.
"The only time he will be willing to negotiate (is) when he feels the military balance has changed on the ground," said Khattab. "And, that is why it is really important for the United States to take the steps and arm the rebels so that Bashar al-Assad will understand that President Obama is getting serious here."
President Obama said Tuesday his "bottom line" for deciding how to hasten a resolution of Syria's civil war is whether any measure is in the best interests of U.S. security.
VOA's Encounter program and Margaret Besheer contributed to this report.