Egyptian spokesman Hossam Zaki said the country's top diplomat sent a letter Tuesday to U.S. Secretary of State Hillary Rodham Clinton urging Washington to "defuse tensions" between the two Mideast nations.
The Scud accusations were raised earlier in April when Israeli President Shimon Peres said Syria was providing the militants with the missiles, which have a far longer range and can carry a much bigger warhead than the rockets Hezbollah used in the past. Israel considers Hezbollah a major threat.
Syria has denied the charges, as has Lebanon's Western-backed prime minister.
The controversy prompted the Obama administration to say last week that it has repeatedly warned Syria that transferring ballistic missiles to Hezbollah could lead to a new war in the Middle East.
Egypt's Foreign Minister Ahmed Aboul Gheit traveled to Beirut on Saturday to discuss the issue and later told reporters there the scud allegations are "lies and are laughable."
When asked by reporters in Beirut whether he came to relay Israeli warnings of a possible attack on Lebanon, Aboul Gheit said that "Egypt does not convey messages from the enemy to a sister" state.
His reference to Israel as an enemy drew a complaint from Israeli ambassador to Cairo, Yitzhak Levanon, who demanded an explanation, the Israeli foreign ministry said.
Egypt later clarified that Aboul Gheit meant Lebanon — not Egypt — considers Israel the enemy.
In 2006, Israel and Hezbollah fought a 34-day war that left some 1,200 Lebanese and 160 Israelis dead. During the monthlong conflict, Hezbollah fired nearly 4,000 rockets at northern Israel, including several medium-range missiles that for the first time hit Israel's third-largest city, Haifa.