Syria threatened Thursday to retaliate for an Israeli airstrike and its ally Iran said the Jewish state will regret the attack.
Syria sent a letter to the U.N. Secretary-General stressing the country's "right to defend itself, its territory and sovereignty" and holding Israel and its supporters accountable.
"Israel and those who protect it at the Security Council are fully responsible for the repercussions of this aggression," the letter from Syria's Foreign Ministry said.
U.S. officials said Israel launched a rare airstrike inside Syria on Wednesday. The target was a convoy believed to be carrying anti-aircraft weapons bound for Hezbollah, the powerful Lebanese militant group allied with Syria and Iran.
In Israel, a lawmaker close to hard-line Prime Minister Benjamin Netanyahu stopped short of confirming involvement in the strike. But he hinted that Israel could carry out similar missions in the future.
The attack has inflamed regional tensions already running high over Syria's 22-month-old civil war.
Israeli leaders in the days leading up to the airstrike had been publicly expressing concern that Syrian President Bashar Assad may be losing his grip on the country and its arsenal of conventional and nonconventional weapons.
Incoming Israeli lawmaker Tzachi Hanegbi, who is close to Prime Minister Netanyahu, said pinpoint strikes are not enough to counter the threat of Hezbollah obtaining sophisticated weaponry from Syria.
"Israel's preference would be if a Western entity would control these weapons systems," Hanegbi said. "But because it appears the world is not prepared to do what was done in Libya or other places, then Israel finds itself like it has many times in the past facing a dilemma that only it knows how to respond to," he added.
He was referring to NATO's 2011 military intervention in Libya that helped oust dictator Moammar Gadhafi.