BEIRUT -- Syrian rebels on Saturday cut a newly built bypass road linking the capital Damascus with the northern city of Aleppo, an activist group said, while state media reported that government troops have secured a strategic highway between the capital and the southern city of Daraa.

The reported fighting came as an activist group said U.S. ambassador to Syria Robert Ford, who left the country last year, met with a rebel commander at a border crossing point with Turkey.

The Aleppo Media Center said Ford met on Thursday with Col. Abdul-Jabbar al-Akidi, head of Aleppo province's rebel military council at the Bab al-Salama border crossing point. It posted a picture and a video of the two men standing on a road just a few meters (yards) outside a fence that appeared to be the border between Turkey and Syria.

The AMC quoted al-Akidi as calling on the U.S. to lift an arms embargo imposed on rebels.

The U.S. so far has balked at sending weapons to the rebels, fearing the arms could end up in the hands of al-Qaida-linked groups or other extremists in the opposition ranks.

Ford was in Turkey to get the opposition to commit to a proposal presented last year at an international conference in Geneva that involves talks with the regime of President Bashar Assad.

The visit follows a decision by Russia and the U.S. this week to convene an international conference to bring representatives of the Assad regime and the opposition to the negotiating table. Such talks would aim at setting up a transitional government. No date has been set.

The plan, similar to the one set out last year in Geneva, calls for talks on a transitional government and an open-ended cease-fire.

Such efforts have run aground in the past, but U.S. Secretary of State John Kerry said there was a chance it might work this time.

"If the political willpower is there and shared, and if people are prepared to compromise reasonably, there is a path forward to be able to have a peaceful solution in Syria," he said late Friday.

The regime and the Syrian opposition have welcomed the idea, but with conditions. The opposition says talks can only begin once Assad and his aides have left. The regime says it will keep fighting the rebels, without saying at which stage it would be willing to halt its fire.

In another border crossing on the Turkish side, two car bombs killed 43 people and wounded 140 others in the town of Reyhanli. Turkish officials blamed the attack on a group linked to Syria, and one called the neighbouring country's intelligence service and military "the usual suspects."

If a Syrian hand is confirmed in the attacks, it would be by far the biggest death toll in Turkey related to its neighbour's civil war. Syria shares a more than 500-mile (800-kilometre) border with Turkey, which has been a crucial supporter of the Syrian rebel cause.

In Israel, meanwhile, an official confirmed that Prime Minister Benjamin Netanyahu will soon meet Russian President Vladimir Putin, an Assad ally.

Israel has expressed concern over what Israeli officials say is an imminent sale of advanced Russian anti-aircraft missiles to Syria. Israel is worried that advanced Russian weapons could reach militant groups hostile to the Jewish state, such as Hezbollah in Lebanon.

Israel has asked Russia to stop supplying "game-changing" weapons to Assad. The Israeli official would not say if the weapons would be discussed. He spoke on condition of anonymity because the Netanyahu-Putin meeting has not yet been announced officially.

In northern Syria, rebels took over two army posts on a desert road that serves as an alternate route into the city of Aleppo after days of fighting, said Rami-Abdul-Rahman, who heads the Britain-based Syrian Observatory for Human Rights.

The regime built the desert road to bypass contested areas after rebels captured the town of Maaret al-Numan in October, cutting the main highway between Aleppo and Damascus.

Meanwhile, state TV said government troops were able to secure the highway linking Damascus with the southern city of Daraa, where the uprising against Assad's regime began more than two years ago.

The TV said troops killed "a large number of terrorists," the term it uses to refer to opposition fighters, in the town of Khirbet Ghazaleh south of Damascus.

The Observatory also reported clashes in the town of Qusair, near the border with Lebanon, between rebels and troops and pro-government gunmen backed by Lebanon's Hezbollah group. It said rebels attacked the village of Abel, near Qusair, and captured it after clashes left seven soldiers dead.

Lebanon's state-run news agency said five rockets fired from Syria struck near another Lebanese border town, Hermel, without causing casualties. Hermel and nearby villages have been targeted by shelling from the Syrian side.

The fighting in the town came a day after U.N. commissioner for human rights Navi Pillay expressed alarm over Qusair, which has been besieged by Syrian troops for several weeks.

On Friday, the Syrian military dropped leaflets over Qusair, urging rebel fighters to surrender, but did not set a deadline for them to do so, according to the office of the Homs governor.

A Syrian provincial official in Homs said the rebels were given 24 hours to surrender, starting 8 a.m. Saturday. He called upon residents who want to leave the city to exit by its southern entrance. He spoke on condition of anonymity because he was not authorized to speak to the media.

The conflict started with largely peaceful protests against Assad's regime in March 2011 but eventually turned into a civil war. More than 70,000 people have been killed in the war, according to the United Nations.