U.S. President Barack Obama telephoned Uzbekistan's president, Islam Karimov, Wednesday to congratulate him on 20 years of Uzbek independence.

The White House says the two leaders pledged to keep working together to build broad cooperation. This would include strengthening contacts between Americans and Uzbeks.

Mr. Obama said he believes that a more prosperous, secure and democratic Uzbekistan benefits both countries.

Uzbekistan was part of the Soviet Union before declaring independence on September 1, 1991.

The United States has praised Uzbekistan for cooperating with NATO operations in Afghanistan. But it also has expressed concern about its human rights record.

A State Department report earlier this month named Uzbekistan as one of the world's top violators of religious freedom.