General Alain Pellegrini, commander of the Unifil force in Lebanon, told a press briefing here that currently the UN was relying on diplomacy to try to end the violations.

"If the diplomatic means should not be enough, maybe it could be considered other ways," he added, referring to the possible use of anti-aircraft missiles equipping French forces in Lebanon.

But Pellegrini made it clear that such a move would require "new rules of engagement drafted and decided here (at UN headquarters)".

He said the issue of Israeli incursions into Lebanese air space was "of major concern" for Unifil.

French Defence Minister Michele Alliot-Marie, who arrived in Washington Wednesday for a four-day visit, raised the issue in talks with President George W. Bush's national security adviser, Stephen Hadley.

On a military level "the situation (in Lebanon) is calm but fragile," Alliot-Marie told Hadley Wednesday. She added that it was "important to avoid anything that may seem to revive the violence" such as Israeli air force flights over Lebanese air space.

UN diplomats played down Pellegrini's suggestion and made it clear that there was no plan to change UN rules of engagement in Lebanon.