Viktor Yushchenko (search), to be sworn in as president Sunday, has pledged to steer Ukraine on a new course, fighting corruption and bringing the former Soviet republic closer to the European Union and NATO while maintaining good relations with Russia.

Secretary of State Colin Powell (search), who arrived in Kiev on Saturday, promised to help the Ukrainians improve their economy and to promote "greater involvement in the trans-Atlantic relationship."

But Yuschenko, a reformer who won a court-ordered election spurred by weeks of protests against his earlier defeat in a fraud-plagued election, could face substantial opposition in the country's largely Russian-speaking east, a stronghold of his rival Viktor Yanukovych (search).

Many in the east fear a rise of Ukrainian nationalism under Yushchenko that could result in discrimination against them. On Saturday, Yushchenko participated in a traditional Ukrainian Cossack ceremony that could heighten those concerns.

In Washington, President Bush called Yushchenko to congratulate him on his election and on "democracy's victory" in Ukraine, White House spokesman Brian Besanceney said.

"The two leaders also discussed their support for the people of Iraq and for democracy in that country," Besanceney said. "They agreed to consult and work closely together in the coming months."

Ukraine has 1,650 troops in Iraq, the fourth-largest contingent in the U.S.-led military operation, and it lost eight troops in an explosion of an ammunition dump on Jan. 9.

"It's going to be an historic moment for the Ukrainian people," Powell told reporters aboard his plane. "They have come through some difficult times, especially through the last three months and I think the international community is pleased that it has been resolved in a peaceful manner and resolved in a way that the will of the Ukrainian people has been determined and was the defining force."

Powell, who is leaving his post shortly, said he expected to discuss economic reform with Yushchenko along with "considerations with respect to the (World Trade Organization) and also greater involvement in the trans-Atlantic relationship."

He said Ukraine's economy "is doing reasonably well and we hope we can enhance" its performance.

In contrast, Russia sent relatively low-level representation — Sergei Mironov, head of the upper house of parliament.

Yushchenko's first foreign trip as president is to be to Russia on Monday, underlining his concern about relations with the Kremlin, but thereafter he embarks on a multi-day swing through the West, including an appearance at the European Parliament.

Also emphasizing Yushchenko's Western orientation will be the presence of NATO Secretary-General Jaap de Hoop Scheffer (search) at the inauguration.

Workers on Saturday hammered on stages hastily constructed on Kiev's Independence Square for the inauguration, as a block away residents of the once sprawling downtown tent camp that housed Yushchenko's supporters for two months tore down their makeshift homes to make way for the hundreds of thousands expected for the festivities.

The tent camp, which housed thousands at the height of the so-called Orange Revolution, named for Yuschenko's campaign color, sprang up within hours of the Nov. 21 presidential election. That vote was later deemed fraudulent by the Supreme Court and annulled, stripping Yanukovych, the former prime minister, of victory.

Yushchenko has pledged to restore the rule of law in this country plagued by rampant corruption, nepotism and red tape.

"I want that we, as a country and as a power, offer our hand to business, I want us to start working for Ukraine," he said.

In the Cossack ceremony, Yushchenko was named a hetman, or Cossack leader, and presented with a golden mace, considered a nationalistic symbol. Ukrainian Cossacks are considered historic defenders of the land against outside oppression.

"I am convinced that ... our forefathers were also dreaming of seeing a democratic Ukraine with free people, with free Cossacks," Yushchenko said at the Kiev ceremony.

Dignitaries from more than 40 countries were expected for the inauguration. The first to arrive was Georgian Parliament Speaker Nino Burdzhanadze, who was a leader of the 2003 protests that forced a government change in her country and that became a model for Ukraine's demonstrators.

"We are happy that everything was resolved by the democratic path," Burdzhanadze said, according to the news agency Interfax.