WASHINGTON/LUCERNE, Switzerland ¨C U.S. Vice President JD Vance is poised to take on his biggest role yet on the international stage as President Donald Trump¡¯s chief negotiator to end the three-month war with Iran, a moment that could shape Vance¡¯s prospects as a White House successor.

The two nations agreed to a provisional peace agreement on Wednesday that suspended hostilities but left core issues unresolved, deferring decisions on Iran¡¯s nuclear program, its support for regional armed proxies and the economically vital Strait of Hormuz to 60 days of talks.

The discussions are a high-risk scenario for ?all sides in the conflict, the broader Middle East, and for Vance¡¯s political ambitions. And the situation remains fluid: Vance cancelled a planned Thursday night flight to Switzerland for the start of talks, ?though the ?White House said the U.S. delegation is ¡°prepared to depart at the first available opportunity.¡±

The fast-moving developments coincide with the publication of Vance¡¯s book on ?his conversion to Catholicism, ¡°Communion,¡± and a media tour to promote it, during which he discussed his faith while positioning himself as the Iran deal¡¯s top booster.

The campaign-style push peaked on Thursday with a White House news conference where Vance laid out U.S. hopes for a final peace deal and offered one of the strongest rebukes of Israel in U.S. history, while also swatting away a ?question about a potential presidential run.

¡°If the Iranians don¡¯t change their behavior, their military and their nuclear program is still destroyed,¡± Vance said. ¡°If they do change their behavior, then they are going to have a transformative relationship ?with the Middle East, and the Middle East will have a transformative relationship with the people of Iran.¡±

Fellow Republicans have underscored the significance of Vance¡¯s high-profile role in the Iran deal.

Sen. Lindsey Graham of South Carolina, a leader in the party¡¯s foreign policy establishment, called Vance the ¡°architect¡± of the peace agreement, and said the vice president should present ?a final deal to the Senate for approval.

Trump joked on Wednesday ?that Vance had little to gain and much to lose from this assignment.

¡°If it works out, I¡¯m going to take the credit. If it doesn¡¯t work out, I¡¯m blaming JD!¡± the president chortled during a news conference at the Group of Seven summit in Evian-les-Bains, France.

Representatives from Vance¡¯s office ?declined to comment for this report.

Trump ran ?for office promising lower prices and an end to what he called ¡°forever wars¡± in the Middle East. Instead, inflation has accelerated, ?and he launched strikes on Iran on Feb. 28. Some Republican allies have accused Trump of granting Tehran major concessions to alleviate the price pressures caused by ?the conflict.

While Trump has touted...