Prime Minister Benjamin Netanyahu bluntly told Barack Obama on Monday that he would never compromise on Israel's security even as the US president sought to reassure him on Iran nuclear diplomacy and pressure him on Middle East peace talks.

In a White House meeting 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 preventing Iran from developing atomic weapons, despite the Israeli leader's deep skepticism over US-led efforts to reach a final international deal to curb Tehran's nuclear program.

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.

"The timeframe that we have set up for completing these negotiations is coming near and some tough decisions are going to have to be made," Obama said.

"It's my belief that ultimately it is still possible to create two states. But it's difficult and it requires compromise on all sides."

But the Israeli leader hit back, telling the president that Israel had taken "unprecedented steps" to advance peace over the last 20 years, and that the ball was now firmly in the Palestinians' court.

"The Israeli people expect me to stand strong against criticism and pressure," Netanyahu told the president.

"Israel has been doing its part, I regret to say the Palestinians haven't," he said, noting that in the past two decades, Israel had both frozen settlement construction, uprooted entire settlements and released hundreds of Palestinian "terrorists."

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. Both were cordial and businesslike. But their differences were clear, and when the talks ended after nearly three hours there was no immediate sign of progress.

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.

Reuters - AFP