In a White House meeting on Monday, overshadowed by the Ukraine crisis, the two leaders avoided any direct clash during a brief press appearance but were unable to paper over differences on a pair of sensitive diplomatic drives that have stoked tensions between them.

Obama assured Netanyahu of his absolute commitment to roll back Iran’s nuclear program, despite the Israeli leader's deep skepticism over US-led efforts to reach a final international deal over Tehran's atomic drive.

But, warning that time was running out, Obama also urged Netanyahu to make tough decisions to help salvage a faltering US-brokered peace process aimed at reaching a framework agreement with the Palestinians and extending talks beyond an April target date for an elusive final accord.

Obama and Netanyahu, who have had strained relations in the past, showed no outright tension as they sat side-by-side in the Oval Office.

Netanyahu arrived in Washington to a veiled warning from Obama that it would be harder to protect Israel against efforts to isolate it internationally if peace efforts failed.

Obama is seeking room for diplomacy with Iran, while Netanyahu, who has stoked US concern in the past with threats of unilateral strikes on Iran's nuclear sites, has complained that sanctions on Tehran are being eased prematurely.

The meeting with Netanyahu marked a new direct foray into Middle East peacemaking by Obama, whose first-term efforts ended in failure.

BA/BA