AMMAN/ANKARA/DOHA: Western governments are ready to increase support to opponents of President Bashar Assad if he rejects a political solution to Syria’s civil war, US Secretary of State John Kerry said yesterday.

Kerry said recent military gains by Assad’s forces were only temporary and that if he believed the counter-offensives against the rebels would be decisive, “then he is miscalculating.”

Kerry, speaking at a news conference in Amman before a meeting of the Friends of Syria group of nations, said several thousand fighters from the Lebanese group Hezbollah were taking part in the conflict with active Iranian support on the ground. Backers of the Syrian uprising were to meet in Amman with the opposition yesterday to discuss a US-Russian proposal for peace talks, as the two-year conflict escalated close to the border with Lebanon.

“Today’s effort ... is part of a political path aimed at ending the violence and bloodshed,” Jordanian Foreign Minister Nasser Judeh told a joint news conference with British Foreign Secretary William Hague before the meeting of the so-called Friends of Syria group. Judeh said the US-Russian proposal was a “turning point.”

Earlier this month, the United States and Russia, which back opposite sides in the Syrian conflict, proposed a peace conference dubbed Geneva 2 to bring together rebels and representatives of President Bashar Assad’s regime.

“The humanitarian crisis underlines the urgency of reaching a political solution and a diplomatic breakthrough,” Hague said.

Eleven top diplomats from Britain, Egypt, France, Germany, Italy, Jordan, Qatar, Saudi Arabia, Turkey, the United Arab Emirates and the United States are attending the meeting.

After initial uncertainty, the acting head of Syria’s opposition National Coalition is to attend the Amman meeting and will be represented by its interim president George Sabra, coalition spokesman Soner Ahmed told AFP.

“The Coalition received a late invitation and has confirmed its participation,” he said.

On the arms embargo on Syria, Hague said: “The decision we need to take in Europe in the next days is about the rules of this embargo. Decisions about sending lethal equipment (to the rebels) is a different matter.”

He said the issue would be discussed with the opposition later on.

Ahead of Amman’s meeting, US Secretary of State John Kerry was also to hold a news conference.

“One of the things we’ll be talking about here in Amman... is what else needs to be done with respect to the military balance on the ground,” a top US official said, urging the Syrian opposition to unify ranks.

A French diplomatic source said the proposed Geneva conference “comes at a time when the regime is taking the lead on the ground as its supporters are getting more and more involved.”

But while the regime has reportedly already proposed the names of several potential envoys to the mooted conference, the opposition has yet to decide whether it will attend.

The National Coalition is to meet later this week in Istanbul, where it is expected to hammer out its stance on the peace effort and take decisions on its leadership.

The diplomatic drive comes against the backdrop of a major push by Syrian regime forces and its allies to retake the rebel stronghold of Qusayr in central Homs province bordering Lebanon.

Syria’s opposition urged fighters across the country to “rush to the rescue” of Qusayr and appealed to the international community to set up a humanitarian corridor to the embattled town.

“The Syrian regime is receiving help from Hezbollah and Iran. That’s an increasing threat to regional stability,” Hague told reporters.

“If the regime were to think they can win a military victory and goes back to whatever was normal before, I think they will be making a terrible error, a catastrophic error. They need a political solution.”

The group says a total of over 90,000 people have been killed since the Syria conflict began in March 2011.

Qatar’s prime minister said that Assad must step down if a political end to Syria’s civil war is to be achieved, echoing similar remarks from Britain. “A political solution must be reached to end the conflict and meet the aspirations of the Syrian people who, as we know, demand changing the regime and changing President Bashar Assad, who insists on killing his people,” Sheikh Hamad bin Jassem Al-Thani told a conference in Doha.

“Any solution must be within this framework,” he said, speaking hours ahead of a meeting in Amman of the Friends of Syria to discuss a US-Russian proposal for peace talks.

Turkey has shut its side of the last border crossing with Syria still controlled by Assad’s government, stepping up security following two deadly bombings this month.

Fifty-one people were killed when twin car bombs ripped through the Turkish border town of Reyhanli in the southern province of Hatay on May 11, heightening fears that Syria’s civil war was dragging in neighbouring states.

Turkey has accused Syria of involvement in the attacks. Damascus has denied any role.