Clinton met for an hour with Egyptian President Hosni Mubarak during a hastily arranged stopover in the Egyptian capital to soothe Arab concerns that Washington is backing off demands for an Israeli settlement halt.
The fears were sparked on Saturday when Clinton, with Prime Minister Binyamin Netanyahu at her side in Jerusalem, praised his government's offer as unprecedented.
She has since tried to clarify the remarks, saying that the Israeli offer does not got far enough.
Still, she has indicated that the Palestinians should resume negotiations with Israel without a full settlement halt as they demand.
On Wednesday, Clinton insisted "our policy on settlement has not changed."
"We do not accept the legitimacy of settlement activity. Ending all settlement activity current and future would be preferable," she told reporters after talks with Mubarak.
"But it is something that I think shows at least a positive movement forward toward final status issues being addressed," she said.
Palestinian Authority President Mahmoud Abbas is sticking to his refusal to resume negotiations until Israel stops building settlements. He rejected the Israeli plan to complete 3,000 housing units in Jewish settlements in the West Bank, and to continue to construct public buildings and other construction in east Jerusalem - a territory Palestinians hope will be their future capital.
After Arab criticism of her comments in Jerusalem on the Israeli plan, Clinton delayed her return to Washington after attending an international conference in Marrakech, Morocco, and flew instead to Cairo.