US President Barack Obama spoke Saturday at the Brookings Institute’s annual Saban Forum in Washington, expressing cautious optimism over both diplomacy aimed at thwarting Iran’s nuclear drive and over Israeli-Palestinian peace efforts.

Obama was interviewed by Haim Saban, an Israeli-American mogul who funds the forum.

The discussion focused in part on the Iranian nuclear deal signed with Tehran in Geneva last month. It also covered the Israeli-Palestinian peace process.

Obama said he could envisage an accord under which Iran maintained a peaceful nuclear program under very stringent international oversight.

Obama said a two-state deal between Israel and the Palestinians was doable, but “is going to require some very tough decisions.” He said, in reference to security arrangements, that the Palestinian Authority would have to “restrain” some of his demands.

Obama wanted to “speak directly to the Israeli people,” Channel 2 reported earlier Saturday, in an effort to allay fears about the deal which has been heavily criticized by the Netanyahu government.

US Secretary of State John Kerry is set to speak later Saturday at the high-end forum focused on Israel’s relationship with the United States, with Netanyahu expected to make his address on Sunday afternoon via webcast.

The prime minister will be interviewed by PBS News host Charlie Rose.

The annual forum, now in its 10th year, is organized by The Saban Center for Middle East Policy and aims to foster dialogue between American and Israeli political figures on the most pressing issues in the Middle East.

This year’s forum comes as ties between the US and Israel have become increasingly strained following the interim nuclear deal signed in Geneva last month between Iran and six world powers including the US, which Netanyahu staunchly and outspokenly opposed.

US officials responded that they were “very frustrated” by the backlash.

On Friday night at the Saban Forum, Foreign Minister Avigdor Liberman said there was zero trust between Israel and the Palestinians, voicing scant hope for a peace agreement by the end of the nine month period allotted for the American-brokered peace talks.

Liberman said negotiations with the Palestinians must start “not from security and not from refugees, but from some simple thing I call trust, confidence, credibility.”

While he expressed gratitude for Kerry’s efforts to bring the two sides together, “to keep this process alive,” and reach a negotiated resolution to the decades-long conflict, Liberman expressed doubt that there’d be an agreement in the coming year.

“To speak frankly,” said Liberman, “I don’t believe it is possible in the next year to achieve [a] comprehensive solution, to achieve some breakthrough, but I think it’s crucial to keep our dialogue, because we live in the same region, we’re neighbors. It’s important at least to think about coexistence.”

Liberman, head of the right-wing Yisrael Beytenu party, said he continued to support a two-state solution, and reiterated his backing for a land and population swap with the Palestinians — a plan which would involve the forced transfer of some Israeli Arabs to Palestinian Authority control.

Turning to the Iranian issue, Liberman reiterated his opposition to Netanyahu’s public airing of dirty laundry with the United States over the interim deal reached with Iran in Geneva last month. “It’s unnecessary to discuss public disagreements publicly,” he said. “I think to cool down the atmosphere is also very crucial today.”

Liberman also warned against a developing Middle Eastern nuclear arms race involving the Saudis, Iran, Egypt and Turkey. He said Iran’s government, headed by President Hassan Rouhani and Foreign Minister Mohammad Javad Zarif, didn’t hold the real power, but the supreme leader Ali Khamenei and Revolutionary Guard did.

He said Iran posed a greater threat to the Gulf countries than it did to Israel. ”The biggest threat from Iranians is not even to Israel, it is first of all to the [Saudi] allies, to the Gulf countries,” he said.

Liberman compared the nuclear deal reached by the US and world powers with Iran and the chemical weapons agreement reached by the US and Russia with Syria. In the Syrian case, the deal was to destroy the chemical weapons and the means of producing them, he said, but in the Iranian case “the centrifuges that were spinning before the agreement continue to spin today” and Iran keeps all enriched uranium.

“It’s really a crucial and big difference between the two deals,” he said, noting that Iran’s end of the bargain was “unacceptable to me and the Israelis” and that Israel “know[s] what the Iranian intentions” are and sees their involvement in terrorist activity in Syria, Lebanon, Iraq and Afghanistan.

Numerous other Israeli politicians are participating in the event — including Justice Minister Tzipi Livni, Energy and Water Resources Minister Silvan Shalom, and Strategic Affairs Minister Yuval Steinitz.