Lebanon's Hizbollah guerrilla group accused the United States of hypocrisy for making a big issue of Israeli claims about an alleged attempt to smuggle weapons to the Palestinians when it provides arms to Israel.
"The American administration makes all this racket over the weapons ship when it presents unlimited military support worth billions of dollars annually to Israel," Hizbollah said in a statement.
Israel seized a ship in the Red Sea last week that it said was carrying 50 tonnes of weapons loaded near Iran with help from Hizbollah. Israeli officials say the shipment was organised with the knowledge of Palestinian President Yasser Arafat.
After a briefing with Israeli intelligence on Thursday, senior US officials said Israel made a compelling case linking senior Palestinian Authority officials to the ship.
In its statement, Hizbollah said the United States had no evidence to prove that the guerrilla group was involved in the weapons shipment.
The US has long deemed Hizbollah - which is backed by Syria and Iran - a terrorist organisation and wants Lebanon to freeze its assets as part of the anti-terror campaign launched after last year's attacks inside the United States.
Lebanon and Syria defend Hizbollah, which helped drive Israel out of south Lebanon in May 2000 after 22 years of occupation, as legitimate resistance.