Ramallah, West Bank (CNN) - The United States will hold both Israel and the Palestinians responsible for any steps that make peace between them more difficult, U.S. Vice President Joe Biden said Wednesday.
Biden, in the region meeting Israeli and Palestinian leaders, repeated strong criticism he made of an Israeli move a day earlier.
He said Tuesday he "condemned" Israel's decision to build 1,600 new apartments on land which both Israel and the Palestinians claim.
The Palestinians contend the area is in East Jerusalem; Israel's Interior Ministry says it is not.
"The substance and timing of the announcement, particularly with the launching of proximity talks, is precisely the kind of step that undermines the trust we need right now and runs counter to the constructive discussions that I've had here in Israel," Biden said Tuesday.
His unusually blunt criticism came after Israel and the Palestinians had agreed earlier in the week to indirect talks to be carried out with U.S. Envoy George Mitchell.
In announcing that both sides had agreed to start the indirect talks - a step toward prospective direct negotiations - Mitchell called on Israel and the Palestinians to avoid any actions that would threaten the talks or their outcome.
Wednesday, Biden repeated that the construction plan undermines the trust needed to reach a peace deal. "We must build an atmosphere to support negotiations, not to complicate them," he said.
Palestinian Prime Minister Salam Fayyad said his side appreciated "the strong statement of condemnation by the U.S. administration."
Biden met with Tony Blair, the former British prime minister now acting as representative of the "Quartet" of powers pushing for peace between Israel and the Palestinians, on Wednesday before meeting Palestinian Authority President Mahmoud Abbas.
Neither Biden nor Abbas took questions from the media in their joint appearance.
Biden arrived in Israel Monday and met with Israeli President Shimon Peres and Israeli Prime Minister Benjamin Netanyahu.
In Jerusalem, he insisted that Washington's position on Israeli security was identical to the Jewish state's own.
"There is absolutely no space between the United States and Israel when it comes to Israel's security - none at all," Biden said.
Peres called Biden a "true friend" of Israel, and Biden said, "It's good to be home."
Biden is the highest-ranking member of the Obama administration yet to visit Israel.
He is scheduled to deliver a major speech at Tel Aviv University Thursday titled "The Enduring Partnership Between the United States and Israel."
Biden also plans a one-day trip to Jordan at the end of the week, when he will meet with King Abdullah.
- CNN's Shira Medding and Kevin Flower contributed to this report.