WASHINGTON (JTA) — U.S. Treasury Secretary Jack Lew suggested that sanctions relief could come before Iran fully suspends its suspected nuclear weapons program — a tactic rejected by Israeli Prime Minister Benjamin Netanyahu.

Lew, speaking Sunday on NBC’s “Meet the Press,” said the United States would not ease sanctions until Iran took tangible steps to suspend its nuclear program, but said sanctions could be “proportionate,” suggesting that interim steps might occasion partial sanctions relief.

“We need to see what they’re going to actually do,” Lew said just days after talks renewed between major powers and Iran over its nuclear program, which Iran insists is peaceful.

“We need to see rolling back their nuclear program,” he said. “And I can tell you that when the time comes, when those movements come, any changes will have to be proportionate.”

In any case, talk of sanctions easing at this stage was “premature,” Lew said.

Netanyahu, appearing on the same show, rejected any partial repeal of sanctions, saying it would signal to other countries that they also could ease sanctions.

“There are a lot of countries that are waiting for a signal, just waiting for a signal, to get rid of their sanctions regime,” he said. “And I think you don’t want to go through halfway measures.”

Netanyahu also rejected as an interim measure unfreezing Iranian assets in the United States, a tactic mooted last week by anonymous U.S. officials who spoke to The New York Times.

He continued to insist on Iran fully dismantling its centrifuges and suspending enrichment before any sanctions relief kicks in.

“The international community adopted very firm resolutions by the [U.N.] Security Council,” he said. “And here’s what those resolutions said: They said Iran should basically dismantle its centrifuges for enrichment. That’s one path to get a nuclear weapon. And stop work on its plutonium heavy water reactor. That’s the other path for nuclear weapons.”

Netanyahu, along with some leading congressional lawmakers, has called for intensified sanctions until Iran meets its Security Council obligations.

The renewed talks between Iran and the Western powers follows the presidential election this summer of Hassan Rouhani, a relative moderate who has called for greater nuclear transparency.

On Sunday, speaking to his Cabinet, Rouhani said Israel was trying to sabotage the new talks.