RAMALLAH, West Bank — Two days after seeking full membership for a State of Palestine in the United Nations, President Mahmoud Abbas, the Palestinian leader, returned to a hero’s welcome here on Sunday, telling supporters that they were part of a “Palestinian Spring” and that he would resume peace talks with Israel only if it stopped building settlements.

On Friday, the United States, the United Nations, Russia and the European Union — known together as the Quartet — urged the Palestinians and the Israelis to return to direct negotiations within a month without preconditions. Since this is close to Israel’s position, leaders there welcomed the plan.

Israel’s foreign minister, Avigdor Lieberman, told Army Radio that Israel “ought to agree to the Quartet proposal, despite all the reservations,” to show its gratitude for American help during the recent ransacking of the Israeli Embassy in Cairo and for President Obama’s United Nations speech last week, opposing the Palestinian membership bid, which was greeted enthusiastically by the Israelis.