Nazarbaev also said Kazakhstan was "ready" for economic and political cooperation with Uzbekistan "to the benefit of the people."
Nazarbaev and Karimov signed several documents during their meeting, including agreements on the protection of classified information, on cooperation in aircraft flight safety, and on tourism.
The two leaders also inked a program on economic cooperation for 2006-08 and a protocol to an agreement on Kazakh-Uzbek border checkpoints.
Nazarbaev said bilateral trade would soar to $1 billion in the coming years, compared with $497 in 2005.
Karimov intensified his administration's efforts to seek economic and political partners within the region following European and U.S. criticism after a bloody crackdown on demonstrators in the eastern city of Andijon in May 2005.