US President Joe Biden has said that if diplomacy does not resolve the Iranian nuclear crisis, America "is ready to turn to other options".
He was speaking in Washington after the first face-to-face talks with Israel's new prime minister, Naftali Bennett.
Mr Bennett praised the president's stance, and his vow to never let Iran acquire nuclear weapons.
The meeting had been delayed for 24 hours following the deadly attack by the IS group at Kabul airport.
Mr Bennett, who took office in June, had said the issue of Iran's nuclear programme would be top of the agenda in his talks with Mr Biden.
Iran considers Israel its arch-foe and lsrael views its nuclear ambitions as an existential threat. Iran says its programme is entirely peaceful but Western powers and the UN's nuclear agency say they are not convinced.
Following 50 minutes of talks at the White House, Mr Biden told reporters the US was willing to take unspecified measures if negotiations with Iran do not get results.
"We're putting diplomacy first and see where that takes us. But if diplomacy fails, we're ready to turn to other options," he said.
In response, Mr Bennett reiterated the point.
"I was happy to hear your clear words that Iran will never be able to acquire a nuclear weapon," he said, "and that you emphasise that you will try the diplomatic route, but there's other options if that doesn't work out."
Mr Bennett's predecessor Benjamin Netanyahu had been close to US President Donald Trump but had clashed with Barack Obama's administration, when Mr Biden served as vice-president. The new prime minister told Mr Biden he looked forward to "working with you now and many years ahead".
Talks to try to revive a frayed 2015 nuclear deal with world powers had been taking place in Vienna but stalled several months ago.
Iran has gradually breached its commitments under the accord in retaliation for the sanctions that Mr Trump reinstated when he pulled the US out of the deal in 2018, which he called "defective at its core".
Iran insists its nuclear activities are peaceful, but it is now enriching uranium to near weapons-grade levels. According to Israel's defence minister, it is only two months away from acquiring the materials necessary for a bomb.
Mr Biden has said he will rejoin the nuclear deal and lift the sanctions if Iran returns to strict compliance. But Iran says he must make the first move.