In February this year, President Vaira Vike-Freiberga authorized the Cabinet chief to sign the 1997 accord, which has remained unsigned over Moscow's protests against a unilateral Latvian declaration claiming land in the adjacent Russian region of Pskov, which was part of the Baltic state before WWII, and demanding that Russia acknowledge the Soviet Union's wartime aggression.
The protests eventually led Latvia to drop the declaration and accept the agreement in its original form.
The treaty will be formalized Tuesday, with PM Mikhail Fradkov signing on the Russian government's behalf.
While in Moscow, Kalvitis will also meet with Russian Economic Development and Trade Minister German Gref and hold talks on natural gas imports with the chief executive of Russia's gas monopoly Gazprom, Alexei Miller.
