The United States says the weekend referendum in Tajikistan failed to meet international standards for transparency. Tajik authorities say an overwhelming majority of voters approved constitutional changes that will, among other things, allow President Emomali Rakhmonov to run for two more terms in office, ending in 2020.

The United States and European governments had been critical in advance of the referendum process in Tajikistan, with the Organization for Security and Cooperation in Europe and other groups declining to send monitors to observe the vote.

Officials here say the announced results, showing both voter turnout and support for the constitutional changes exceeding 90 percent, have only reinforced their skepticism about the exercise.

Some 50 constitutional amendments were on the ballot to be approved or rejected collectively. The most significant was a proposal allowing President Rakhmonov, whose current mandate expires in 2006, to seek two more seven-year terms and thus possibly remain in power until 2020.

At a briefing here, State Department Spokesman Philip Reeker said the United States is "concerned" by the apparent outcome of the vote. "A constitutional referendum in that country should meet international standards for transparency, and, unfortunately, this exercise that was held over the weekend did not meet those standards," he said. "And we are urging the Tajik government to test its leadership and its policies through regularly-scheduled free and fair elections."

Members of the political opposition in Tajikistan had complained that the referendum was hastily arranged and allowed for little national debate, and they have accused the government of falsifying the results.

President Rakhmonov, the country's leader since 1992, has said he has not decided whether to seek re-election, but opponents say they fear he may never willingly step down.

In its annual global human rights report, issued in March, the State Department said Tajikistan's government was "authoritarian" and dominated by Mr. Rakhmonov and an inner circle of fellow natives from the central Kulyab region.

It described the country's 1999 election, in which Mr. Rakhmonov won his current term in office, as "seriously flawed" and neither free nor fair.