A political solution is the only way to end the violence, Foreign Affairs Minister John Baird and his German counterpart stressed Thursday after bilateral talks in Ottawa.
Both men expressed concern about reports that Syrian President Bashar Assad has received sophisticated Russian anti-aircraft missiles.
"Syria has received the first shipment of Russian anti-aircraft S-300 rockets," Hezbollah's Al-Manar TV quoted Assad as saying.
The Syrian leader added: "All our agreements with Russia will be implemented and parts of them have already been implemented."
Baird called the reports regrettable, if true, while German Foreign Minister Guido Westerwelle characterized the development as unappreciated.
He said he'd recently spoken to his Russian counterpart.
"I underlined how important it is that no one is doing anything which could spoil this conference for the political solution between the different parties," Westerwelle said.
The U.S. and Russia were to meet later this week in Geneva to hash out a plan to get both sides together for peace talks but the Syrian National Coalition, one of the major opposition groups, suggested that for now there's no place for talks.
"The talk about the international conference and a political solution to the situation in Syria has no meaning in light of the massacres that are taking place," a spokesman for the Syrian National Coalition, Khalid Saleh, told reporters in Istanbul.
More than 70,000 people have been killed in the 26-months-old Syrian conflict.
Baird said he echoed Westerwelle's belief that opposition groups have a responsibility and an obligation to be part of the talks.
"If there's to be a political solution, obviously both sides have to be at the table and we hope they'll avail themselves of this American and Russian leadership," Baird said.
"The only way to bring an end to the suffering of the Syrian people is a political solution. Over the past two and a half years we've seen more arms have only led to more bloodshed and more suffering."
The shipment of the missiles, if confirmed, comes just days after the European Union lifted an arms embargo on Syria, paving way for individual countries of the 27-member bloc to send weapons to rebels fighting to topple Assad's regime.
Westerwelle made it clear, however, that it doesn't mean weapons shipments are imminent.
"This option is now on the table, which does not mean that they announced any kind of delivering of weapons, they just said that they want to have the option," he said.
Canada won't follow suit, Baird stressed.
The concern with the influx of weapons isn't just about them making it into the wrong hands but also the start of a arms race between opposition groups and the Assad government and the spillover of the conflict into the rest of the Middle East.
Israel has carried out several airstrikes in Syria in recent months that are believed to have destroyed weapon shipments bound for Hezbollah, the Lebanese Shiite group that along with Iran and Russia is a staunch Assad ally. It is not clear whether Israeli warplanes entered Syrian airspace in these attacks.
The involvement of Iran and Hezbollah in Syria was cited by the opposition coalition as a factor for their withdrawal from talks.
"The National Coalition will not participate in an international conference and will not support any efforts in light of Iran's malicious invasion of Syria," Saleh said.
With the Russian missiles in Syria's possession, the Israeli air force's ability to strike inside the Arab country could be limited since the S-300s would expand Syria's capabilities, allowing it to counter airstrikes launched from foreign airspace as well.
The S-300s have a range of up to 200 kilometres (125 miles) and the capability to track and strike multiple targets simultaneously. Syria already possesses Russian-made air defences, and Israel is believed to have used long-distance bombs fired from Israeli or Lebanese airspace.
When Israeli warplanes struck near the capital of Damascus, targeting purported Iranian missiles intended for Hezbollah earlier this month, Syria did not respond.
But on Wednesday, Syrian Foreign Minister Walid al-Moallem told Lebanon's Al-Mayadeen TV that Damascus "will retaliate immediately" if Israel strikes Syrian soil again.
— With files from The Associated Press
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