WASHINGTON — Barack Obama spoke directly with his vanquished rival Hillary Rodham Clinton on Wednesday and expressed optimism they could achieve party unity after their bruising battle for the Democratic presidential nomination. He also accused Republican rival John McCain of supporting a "plan for staying, not a plan for victory" in Iraq.

As he traded jabs with McCain over national security policy, Obama visited the Senate where Democrats and Republicans shook his hand and congratulated him. The Illinois senator disclosed he had spoken with Clinton, who was not in the Senate, earlier on the day after he claimed the nomination and she stopped short of conceding.

"I just spoke to her today, and we're going to be having a conversation in coming weeks. And I'm very confident how unified the Democratic party's going to be to win in November," Obama told reporters as he left the Senate.

Asked if Clinton indicated she planned to concede, Obama replied, "It wasn't a detailed conversation. As I said, I'm very confident of how we're going to be able to bring the party together." He dismissed a question about her refusal to concede after the final two primaries Tuesday night by saying she was "understandably focused on her supporters."

Obama and Clinton ran into each other backstage at the American Israel Public Affairs Committee meeting, which they addressed separately Wednesday morning.

A day after welcoming Obama to the general election campaign, McCain said in a morning television interview, "I think he has exercised very bad judgment on national security issues and others."

Obama used his speech at the AIPAC meeting to reassure Jewish voters of his support for Israel and criticize McCain's promise to keep U.S. troops fighting in Iraq.

"Keeping all of our troops tied down indefinitely in Iraq is not the way to weaken Iran, it is precisely what strengthened it," Obama said in a speech in which he said the security of the Jewish state was sacrosanct.

Elsewhere, Obama's accomplish in becoming the first black ever to win a major party presidential nomination drew Secretary of State Condoleezza Rice's attention.

"The United States of America is an extraordinary country. It is a country that has overcome many, many, now years, decades, actually a couple of centuries of trying to make good on its principles," said Rice, the first female black secretary of state in history, serving in a Republican administration.

"And I think what we are seeing is an extraordinary expression of the fact that 'We the people' is beginning to mean to all of us."