But Barak's chief-of-staff Danny Yatom, accompanying the new prime minister on his maiden US visit, stopped short of calling a 15-month timeframe a deadline for a comprehensive peace in West Asia.

``The estimate of both the Prime Minister and the US President is that this is the time period necessary to see... how the process will unfold,'' Yatom told Israel Radio from New York.

``The estimate is that within around 15 months, about a year and a half, we'll be able to say if we reached a breakthrough or not. I hope we'll reach a breakthrough.''

Barak has held several rounds of talks with Clinton and top US officials on reviving peacemaking after the election defeat of Israeli right-winger and former prime minister Benjamin Netanyahu, and will hold further meetings with Clintontomorrow.

Foreign Minister David Levy deflected criticism that setting a target would encourage Arab partners to resist a deal in hopes of forcing Israel into last minute concessions. ``If we set that this is the target, it shows that Israel is not interested in dragging things out and expects the other side to make an effort in order to finally end this conflict,'' Levy said.

Chief Palestinian negotiator Saeb Erekat sidestepped a question about whether Barak's target date was realistic, but said Palestinians wanted to move quickly to clinch a deal.