U.S. Secretary of State Hillary Clinton dismissed on Friday reports that administration of former U.S. President George W. Bush had an understanding under which Israel could keep expanding settlements on the West Bank.

Dov Weisglass, chief of staff to former Prime Minister Ariel Sharon, wrote in an op-ed piece published this week in the Yedioth Ahronoth daily that the Bush administration had secretly agreed to expanding Jewish settlements on the West Bank within their existing boundaries.

Speaking to reporters in Washington, Clinton sought to undercut Weisglass' argument, saying there was no acknowledgment of any such agreement in the official negotiating record between Israel and the Bush administration.

"There is no memorialization of any informal and oral agreements. If they did occur, which of course people say they did, they did not become part of the official position of the United States government," Clinton said at a news conference with Turkish Foreign Minister Ahmet Davutoglu.

"And there are contrary documents that suggest that they were not to be viewed as in any way contradicting the obligations that Israel undertook pursuant to the road map," Clinton added. "And those obligations are very clear."

Clinton's hard line suggests that U.S. President Barack Obama has no intention of relenting on his call for a settlement freeze by Prime Minister Benjamin Netanyahu.

The United States wants Israel to keep its commitment under the 2003 "road map" peace plan to halt all settlement activity, including so-called "natural growth," under which new homes are built within existing enclaves for growing settler families.

Netanyahu on Monday defied the U.S. demand, saying Israel would keep building in existing settlements on territory Israel captured during the 1967 Six-Day War.

Ex-Mossad chief: Bush showed understanding for Israel's position on settlement blocs

The previous U.S. administration expressed understanding for Israel's demand to retain large West Bank settlement blocs as part of any final status accord with the Palestinians, Ephraim Halevy, the former head of Israel's spy agency, Mossad, told Israel Radio on Saturday.

In the exchange of letters between former President George W. Bush and then-Prime Minister Ariel Sharon, the U.S. acknowledged that the prevailing circumstances on the ground would make it unrealistic to expect Israel to withdraw wholly to the pre-1967 armistice lines, Halevy told Israel Radio.

Halevy added that the road map document includes explicit recognition of the Palestinians' political rights in Jerusalem, according to Israel Radio.

The former Mossad chief added that Israel has no say in determining whether it satisfactorily met its obligations under the road map. The international Quartet - the U.S., Russia, the European Union, and the United Nations - is the only body authorized to make such a determination, Halevy told Israel Radio.