The White House on Thursday warned Syria not to transfer weapons to Hezollah, AFP reported, on the heels of a reported Israeli strike on an arms convoy near the Lebanese border on Tuesday night.
"Syria should not further destabilize the region by transferring weaponry to Hezbollah," said Ben Rhodes, a US deputy national security advisor, according to AFP.
Meanwhile, UN Secretary-General Ban Ki-moon expressed "grave concern" on Thursday over reports that Israeli jets bombed a convoy near the Lebanese border, apparently hitting weapons destined for Lebanese militant group Hezbollah.
"The Secretary-General calls on all concerned to prevent tensions or their escalation ... and to strictly abide by international law, in particular in respect of territorial integrity and sovereignty of all countries in the region," Ban's press office said in a statement.
Syria summoned the head of a United Nations mission in the Golan Heights
on Thursday to protest against the Israeli air raid which Damascus said
is a violation of a disengagement accord that followed the last major
war between the two countries.
However, UN peacekeepers in a demilitarized zone between Syria and Israel were unable to verify the Syrian complaint that Israeli planes had flown over the Golan Heights area, a spokesman for Ban said on Thursday.
"UNDOF (the peacekeeping mission) did not observe any planes flying over the area of separation and therefore was not able to confirm the incident. UNDOF also reported bad weather conditions," UN spokesman Eduardo del Buey told reporters.
Syria's ambassador to Lebanon said that Damascus had the option of a "surprise decision" to respond to Israel's alleged strike on a research center on the outskirts of the Syrian capital.
Syria could take "a surprise decision to respond to the aggression of the Israeli warplanes," Ali Abdul Karim Ali was quoted as telling a Hezbollah-run news website.
"Syria is engaged in defending its sovereignty and its land," he added, without spelling out what the response might entail.
Syria also sent a letter to the United Nations Security Council concerning the reported air strikes on its territory, said H.E. Mr. Masood Khan, Permanent Representative of Pakistan and President of the Security Council for the month of January.
While they are still reviewing the letter, Khan noted that it included no request from Syria for an emergency meeting and that no such meeting of the Security Council is planned, though they are "monitoring the situation" carefully.
"Things are developing rapidly," Khan said at a press conference. "Council members are aware of the situation."
Syria and Israel have fought several wars and in 2007 Israeli jets reportedly bombed a suspected Syrian nuclear site, without retaliation.
In the wake of reported Israeli air strike on a Syrian weapons center, Iran also issued a threat to Israel on Thursday.
The Iranian regime's English language mouthpiece, Press TV, quoted a deputy foreign minister as saying that the "strike on Syria will have serious consequences for Tel Aviv." The official did not elaborate.
Last week, a senior adviser to Iran's supreme leader said that any attack on Syria would be seen by Tehran as an attack on itself. The official, Ali Akbar Velayati, said the regime of Basher Assad is a central component of the "resistance front."
Meanwhile, Lebanon's militant group Hezbollah condemned on Thursday an Israeli attack which it said targeted a Syrian research center, saying it was an attempt to thwart Arab military capabilities and pledging to stand by its ally President Bashar Assad.
"Hezbollah strongly condemns this new Zionist aggression on Syria,” the group said in a statement, calling for "wide-scale condemnation from the international community," the group said in a statement.
The group "expressed its full solidarity with Syria's leadership, army and people."
Sources said on Wednesday that Israel Air Force jets bombed a convoy near Syria's border with Lebanon, apparently targeting weapons destined for Hezbollah. Syria denied the reports, saying the target had been a military research center.
Russia said on Thursday it was very concerned about reports of an Israeli air attack deep inside Syria near Damascus and that any such action, if confirmed, would amount to unacceptable military interference in the war-ravaged country.
"If this information is confirmed, then we are dealing with unprovoked attacks on targets on the territory of a sovereign country, which blatantly violates the UN Charter and is unacceptable, no matter the motives to justify it," the Russian Foreign Ministry said in a statement.
Syrian state television accused Israel of bombing a military research center at Jamraya, between Damascus and the nearby border. Syrian rebels disputed that, saying their forces had attacked the site.
Russia has been trying to shield Syrian President Bashar Assad from international pressure to end the civil war against opposition forces that has ravaged the country over 22 months and killed an estimated 60,000 people. Moscow has repeatedly spoken against any foreign interference in Syria, especially military action.
Michael Wilner, Jerusalem Post correspondent contributed to this report