"For us this route will be one of the main ways to supply world markets," he said on Tuesday at a ceremony where he signed bilateral agreements with Azerbaijan President Ilham Aliyev.
The Baku-Tbilisi-Ceyhan pipeline to open on Wednesday will transform the Caucasus and Turkey into an energy bridge between the Caspian and the rest of the world.
But Kazakhstan's participation in the project has until now remained under question as it navigated the choppy diplomatic waters between Washington and Kazakhstan's former overlord, Moscow.
The pipeline is expected to go into full operation six months from now and become a major competitor to the traditional export routes for Caspian oil that lie through Russia.
Nazarbayev joked that the pipeline should now be renamed Aktau-Tbilisi-Ceyhan after Kazakhstan's Caspian port city.
But he added that the republic would keep open other options for exporting its oil, production of which is expected to reach 150 million tons a year in 2015.
Another pipeline targeting growing Chinese energy demand will be opened as early as December, Nazarbayev said, adding that "there is the possible variant of exporting oil through Iran in the future."