The United States said Monday that Tunisia's presidential election, won overwhelmingly by incumbent President Zine al-Abidine Ben Ali, fell short of what was expected from the reform-minded North African country. U.S. officials cited "serious flaws" that limited the campaigns of opposition candidates.

The State Department criticized the Tunisian election in measured terms, saying opportunities for the opposition to contest the election had been limited, and that the United States hopes to see a greater degree of political reform in that country in the future.

According to official figures released Monday, President Ben Ali, won a fourth term in office by drawing more than 94 percent of the vote in a four-way contest.

Though Tunisian government officials said there had been no serious irregularities, opposition candidates called the election a sham and a missed opportunity for the country.

At a news briefing, State Department Deputy spokesman Adam Ereli said there were "questions" about the degree to which the elections were fully contested.

He said the ability of opposition candidates to "meaningfully" compete is an important indicator of the strength of democratic institutions any country, including Tunisia, which has been regional reform leader in other areas. "Tunisia has successfully opened up opportunities over the years in economic reform, in education and women's rights. They've been very progressive and have shown real far-sightedness. Our concern is that Tunisia meet the same standards for opportunities in political participation," he said.

Mr. Ereli noted that Tunisia itself, a longtime U.S. friend and ally in the war on terrorism, had endorsed the expansion of democracy and freedom of expression in the Middle East in the Arab League's Tunis summit declaration last May.

He said the issue of the fairness of the presidential election campaign had been a subject of ongoing diplomatic dialogue between the United States and Tunisia.

When asked flatly if the United States was "disappointed" with the outcome, he said instead that U.S. officials are concerned that Tunisia "has fallen short of its own potential."

A U.S. diplomat who spoke to reporters here on terms of anonymity said there were "serious flaws" in the election process, including curbs on media access by the opposition and instances of intimidation and harassment.

He denied that the Bush administration was soft-pedaling its criticism because of Tunisia's status as an ally, saying the State Department's language was geared to produce "movement in a positive direction" rather than causing reform opponents there to "dig in their heels, and fail to open up."