Ankara, Turkey ? A party with Islamic roots won a landslide victory in Turkish elections Sunday and its leader quickly moved to calm fears of a shift away from secularism in this key U.S. ally.

At a huge victory celebration, Justice and Development Party leader Recep Tayyip Erdogan told supporters: “We will not spend our time dizzy with victory. We will build a Turkey where common sense prevails.”

Erdogan immediately sought to allay fears his party, which has roots in Turkey’s Islamist movement, would move the nation toward religion. He pledged support for secularism, Turkey’s bid to join the European Union and even said he would reluctantly support a U.S. strike on Iraq if it is approved by the United Nations.

The party’s win was fueled by voter anger at Turkey’s worst economic crisis since World War II and disillusion with the political elite. In an election in which all incumbent parties lost, the party benefited from not serving in the last parliament and having a clean image.

By emphasizing social and economic issues, the party gathered a strong following and avoided angering the powerful and staunchly pro-secular military and courts, which have pushed earlier pro-Islamic parties from power. It is not clear how the military will react to the win.

“I voted for Justice because we have no trust left in the other parties,” said Hatice Bilal, 43, a civil servant. “We want an end to poverty.”

With 99 percent of the vote counted, Erdogan’s party had 34 percent support and the center-left Republican People’s Party had 19 percent, the Anatolia news agency reported.

Projections by Anatolia showed the Justice party taking 361 seats, meaning that it could form a government without any coalition partners the first time in 15 years that a party has been able to rule alone.

Despite leading the Justice party, Erdogan has been banned by the elections board from standing as a candidate because of a jail sentence he served in 1999 for publicly reading a poem deemed anti-secular. It is not clear whom the party will name as prime minister or whether lawmakers will try to end the ban.

Erdogan said his government’s first priority will be to “speedily pursue the EU membership process.” He said that his government will “follow an economic program to integrate the country with the world.”

He later said that he would support a war against Iraq if it is approved by the United Nations.

“We do not want war, blood, tears and dead in our region,” Erdogan said. However, he added, “We are obliged by the United Nations decisions … The important thing is the United Nations’ decisions.”

Turkey, a NATO-member country, hosts U.S. warplanes at its southern Incirlik air base, which was a staging point for attacks on Iraq during the Gulf War. Its support would be key to any U.S. operation. Washington also strongly supported Turkey’s push to take over the international peacekeeping force in Afghanistan.

Prime Minister Bulent Ecevit’s party had only 1 percent of the vote.