US concern over allegations that Syria has been supplying Scud missiles to Hezbollah serves to encourage Israel to attack Lebanon, the Lebanese Shiite militant group said on Saturday.

Israeli President Shimon Peres has accused Damascus of providing Hezbollah with the missiles, prompting Washington to warn that the trade "potentially puts Lebanon at significant risk."

"With this position, (the Americans) are encouraging Israel to carry out an aggression against Lebanon that they are trying to endorse at the international level," Hezbollah MP Ali Fayyad told AFP.

"The United States is thus placing itself in a position of complicity in the event of aggression and it will have to take responsibility," he said.

Fayyad said that Hezbollah, which is backed by Syria and Iran, did not comment on "Israeli inventions on its arsenal" but Peres's accusation on Tuesday had made "the situation more tense than before."

Such statements "exacerbate tension and directly threaten the stability of the region," the MP said, accusing Washington of trying "to cover up its failures as well as those of Israel" in the Middle East.

According to Arab media and some think-tanks, Syria has been sending some of its own arsenal of Scuds to Lebanon, an allegation denied by Damascus.

"We are obviously increasingly concerned about the sophisticated weaponry that is allegedly being transferred," White House spokesman Robert Gibbs said on Wednesday.

"We have expressed our concerns to those governments and believe that steps should be taken to reduce any risk and any danger," Gibbs said, apparently referring to the Israeli and Syrian governments.

Israel and Hezbollah in 2006 fought a 34-day war which killed 1,200 Lebanese, mostly civilians, and more than 160 Israelis, mainly soldiers.