Marat Tazhin said the concerns came up in connection with his country's bid to chair the Vienna-based Organization for Security and Cooperation in Europe in 2009.
In talks on May 9, Tazhin said Rice tied U.S. support for Kazakhstan's bid to chair the OSCE to political reform.
Tazhin said he stressed to Rice that his country plans to enact liberalization through constitutional changes.
Last December, the OSCE postponed until later this year a vote on the country's bid to chair the security and rights group, saying Kazakhstan must do more to meet its standards.
The OSCE Chairman in Office, Spanish Foreign Minister Miguel Angel Moratinos, said during a visit to Astana in April that he hoped to achieve a consensus in November to hand the body's presidency to Kazakhstan in 2009.