JERUSALEM — In the clearest admission ever made by an Israeli leader, former prime minister Shimon Peres Monday said Israel had "built a nuclear option not in order to have a Hiroshima but an Oslo."

Peres, who is credited with constructing Israel's nuclear facility, said, "We thought the reasons Israel was attacked five times without any provocation was because some of our neighbors thought they could overpower us, and we wanted to create a situation in which this temptation would no longer exist.

"I think without it, we would not have the Oslo Agreement."

Peres, who was visiting Jordan's King Hussein in his Amman palace, also urged the United States to maintain its role as mediator in the peace process and warned that an American withdrawal from the negotiations would be a blow to the region.

Peres also told reporters that Americans "are playing a positive role [in the negotiations], and if they retreat from the Middle East the region would not be better off, politically or otherwise."

Referring to Washington's reported intention of walking away from the stalled peace process, Peres said "I think we must put pressure on the U.S. not to leave the Middle East."

Peres also met Crown Prince Hassan and addressed a U.N. seminar on leadership for Jordanian, Israeli and Palestinian youth.

His visit is part of a series of meetings between the Jordanian rulers and Labor's leadership: Knesset member Yossi Beilin visited Amman on Sunday and Labor leader Ehud Barak was scheduled to meet Hussein Tuesday.

"We talk like friends, his concerns are my concerns," Peres said, describing his relations with Hussein.

Peres criticized Prime Minister Benjamin Netanyahu's government for not striving toward an agreement with the Palestinians "as energetically as it should" and called on Netanyahu to leave the subject of Jerusalem to the final-status talks with the Palestinians.

Addressing a gathering of 150 officials, professors and students in Amman, Peres said he disagreed with Netanyahu's policy of expanding settlements and his government's decision to extend Jerusalem's municipal area.

"Maybe the time has come to change the government in Israel," Peres said.