The US readied a package Saturday of up to $130m in non-lethal military aid to Syrian opposition forces while European countries consider easing an arms embargo, moves that could further pressure the government of President Bashar al-Assad.

US secretary of state John Kerry was expected to announce the plans about the defensive military supplies at a meeting Saturday that was bringing together the Syrian opposition leadership and their main international allies.

The supplies possibly could include body armor, armored vehicles, night vision goggles and advanced communications equipment.

US officials said the details and costs were to be determined at the meeting. They spoke on condition of anonymity because they were not authorized to publicly discuss Kerry's announcement.

Kerry met with Syrian opposition leader Moaz al-Khatib before the conference began.

In the latest clashes, Syrian troops backed by pro-government gunmen battled rebels Saturday in a strategic area in Homs province near the Lebanese border, according to activists and state media in Damascus, the Syrian capital.

President Barack Obama has said he has no plans to send weapons or give lethal aid to the rebels, despite pressure from Congress and even some administration advisers.

Since February, the US has shipped food and medical supplies directly to the Free Syrian Army. The aid was expanded later to include defensive military equipment. So far, the US has provided an estimated $117m in non-lethal aid to the Syrian opposition, according to the White House.

Britain and France are leading a push to modify the European Union's arms embargo on Syria to permit weapons transfers to the rebels by the end of next month. The embargo is to expire at the end of May unless it is extended or revised.

Those in favor of the change say there have been no decisions on whether to actually supply the rebels with arms. They argue that allowing such transfers would increase the pressure on Assad. US officials say they support testing this strategy.

Germany and the Netherlands, however, are said to be reluctant to support the step because they fear it would lead to further bloodshed.

Kerry said before leaving Washington that the conference aim was to get the opposition and all prospective donors "on the same page" with how Syria would be governed if and when Assad left power or was toppled.

With Syria's civil war in its third year, the US and its European and Arab allies are struggling to find ways to stem the violence that, according to the United Nations, has killed more than 70,000 people. Despite international pressure, Assad has managed to retain power far longer than the Obama administration expected.

"We need to change President Assad's calculation, that is clear," Kerry told US senators Thursday. He said the Assad government's survival largely depends on the continued support it gets from Iran, its proxy Hezbollah, and Russia.

"That equation somehow has to change," Kerry said.

John McCain, one of the top Republicans on the Senate armed services committee, wants US military action, including airstrikes on government aircraft and weapons. But he does not want to send in American soldiers.

He said the steps he recommends would give moderate and secular opposition forces a better chance to succeed without having to depend on extremist groups that are supporting the rebels.

The US is not opposed to other countries arming the rebels, provided there are assurances the weapons do not get to extremist groups that have gained ground in the conflict.

Kerry said that Assad, his inner circle and supporters in Iran and Russia have yet to be persuaded to enter negotiations with the opposition and allow for a political transition.

He said he had not given up on persuading Moscow to reverse its support for Assad.

Kerry planned to meet Russian Foreign Minister Sergey Lavrov next week in Brussels on the sidelines of a Nato-Russia Council meeting.

"My hope is still that the Russians can be constructive," he said.