"A political party, in order to be viable, is one that professes peace, in my judgment, in order that it will keep the peace," the president said after an apparently strong showing by Hamas in Palestinian parliamentary voting.
"And so you're getting a sense of how I'm going to deal with Hamas if they end up in positions of responsibility. And the answer is: not until you renounce your desire to destroy Israel will we deal with you." He made his remarks in an interview with The Wall Street Journal.
The United States and other sponsors of a plan to draw Israelis and Palestinians back to the peace table will reassess peace prospects next week in light of the Palestinian voting.
Secretary of State Condoleezza Rice, U.N. Secretary-General Kofi Annan and other members of the "Quartet" of would-be international peacemakers will meet Monday in London, State Department spokesman Sean McCormack said.
The Quartet is on record against allowing Palestinian Authority cabinet status for anyone who has not renounced violence or recognized Israel's right to exist. Hamas has done neither.
Early exit polling suggested Hamas placed a close second to the ruling Fatah Party, and the rival groups could end up forming a governing coalition.
Strong voter support for Hamas, responsible for dozens of suicide bombings against Israel, places the militant and political group inside the Palestinian political system for the first time.
Hamas boycotted earlier parliamentary elections, and Israel objected early on to allowing it to participate in Wednesday's voting. Israel has warned it will not negotiate with any Palestinian government that includes Hamas.
Before the election, Hamas leaders said they would seek service ministries in a future cabinet, such as health, education and welfare. They said they would leave diplomacy, including contacts with Israel, to others.
Rice has said Hamas represents a "practical problem" for Israel in pursuing peace contacts. Hamas also poses a practical problem for the United States and European nations that list it as a terrorist organization.
"We don't deal with Hamas. And under the current circumstances, I don't see that changing," McCormack said.
Even so, he did not rule out dealing with the Palestinian Authority at large, which will still be led by Palestinian President Mahmoud Abbas. McCormack also would not say whether the United States would withhold aid to the Palestinians if Hamas is in the government, although other U.S. officials have indicated that could happen.
"As for what policies the United States and the quartet pursues based on what kind of Palestinian Authority there is, what kind of policies they pursue, we'll see" what the elections produce, McCormack said. "We're not there yet."
The Quartet — which involves the United States, the United Nations, the European Union and Russia — is to meet a day ahead of a separate international gathering on the rebuilding of Afghanistan.
In December, the group issued a strongly worded statement noting a "fundamental contradiction" between armed militia activities and construction of a democratic state. The goal of the international peace effort is to erect an independent, democratic Palestine in areas where Palestinians already are concentrated alongside Israel.
The Quartet statement said that "a future Palestinian Authority Cabinet should include no member who has not committed to the principles of Israel's right to exist in peace and security and an unequivocal end to violence and terrorism."