When President Obama hosts Israeli Prime Minister Benjamin Netanyahu at the White House on Monday, a fundamental division will be on display: Obama is pushing for a nuclear deal with Iran on terms the Israeli leader has already rejected.

Obama is closer than ever this year to his campaign goal of a nuclear accord with Iran. As Netanyahu and thousands of pro-Israel Americans visit Washington for the annual American Israel Public Affairs Committee (AIPAC) policy conference, which opens this weekend, Obama’s challenge will be to show how an improving relationship with Iran does not damage ties with Israel.

The AIPAC meeting showcases Israel’s unique position among U.S. allies and its strong influence on Capitol Hill. Hundreds of delegates will lobby Congress on issues including Iran, Middle East peace and the effect of the Syrian civil war on Israel. A bipartisan effort to enact additional sanctions against Iran, derailed by the White House but championed by AIPAC, will be a main topic.

Treasury Secretary Jack Lew and Secretary of State John F. Kerry will address the forum. Obama will not, although he has done so in the past. Lew’s department is in charge of enforcing the heavy net of sanctions that helped force Iran to enter serious talks.

An Oval Office visit between the U.S. and Israeli leaders has become customary on the sidelines of the AIPAC conference. “The president looks forward to discussing with the prime minister progress in Israeli-Palestinian negotiations, developments in Iran, and other regional priorities,” White House press secretary Jay Carney said Friday.

Obama is expected to press Netanyahu to continue peace talks with the Palestinians as negotiations move into a critical phase.

Israel is due to release a final group of Palestinian prisoners at the end of March under an agreement to get peace talks started last year. It’s a politically risky move that has caused Netanyahu trouble within his government coalition. The United States wants Netanyahu to stick to the plan, but U.S. and Israeli officials acknowledged this week that he may seek additional concessions.

Palestinians, for their part, are likely to put off taking further steps until the last of the prisoners are free.

Kerry said this week that success depends on each side’s will to forge ahead.

“I wouldn’t be pursuing it if I didn’t think it was worthwhile,” Kerry said during a roundtable interview with reporters Wednesday. “I hope we’re not wasting our time. I hope very much that we’re able to get both parties to do what is necessary to enter the most critical stage of this.”

Kerry brought the two sides to the table under heavy pressure last summer for what have been the most sustained peace talks in years. Kerry had originally set a deadline of late April to announce a final deal but acknowledged this week that his timetable has shifted.

He is now trying to get both sides to agree to what he calls a framework for a final deal. The interim agreement would set the terms for arduous and highly technical negotiations over a final peace deal to end the decades-long conflict. It’s a hard sell to both sides, because it is tantamount to a final deal and would box the leaders in to concessions they have long resisted.

If both sides agree, “then we get into the final negotiations,” Kerry said in the interview. “I don’t think anybody would worry if there’s another nine months or whatever it’s going to be to finish up” a peace treaty, Kerry said.

Palestinian Authority President Mahmoud Abbas will visit the White House on March 17. Kerry’s last visit with Abbas went poorly, according to a Palestinian newspaper. Kerry proposed concessions at meetings in Paris more than a week ago that included a Palestinian capital in only part of East Jerusalem instead of the whole district, Al-Quds reported.

But Iran is expected to dominate discussions next week in Washington. Netanyahu opposed the placeholder international agreement reached last fall as overly generous to a nation he views as a mortal threat and insufficient to guarantee that Iran could not manufacture a nuclear weapon.

Israel is advocating a much tougher line in the final deal under negotiation but isn’t a party to the talks. The outline for the proposed final deal is already clear, and it envisions allowing Iran to retain at least a modest domestic uranium enrichment program. Netanyahu, however, has said Iran must not be left with any nuclear manufacturing capability.

“Zero enrichment, zero centrifuges, zero plutonium,” Netanyahu said last week at a news conference with German Chancellor Angela Merkel.