The offer came as Poland finalised an agreement to host elements of a US missile defence shield that Moscow describes as a threat to its national security.
Ukraine's foreign ministry said Kiev could invite European partners to integrate their early warning systems against missile attacks.
Ukraine is also ready to deal with "foreign countries interested in getting information about the situation in space," the ministry statement said.
Russia's parliament voted to withdraw from a bilateral missile radar accord in January in response to Ukraine's application for membership of the Nato military alliance.
Symbolic gesture
Analysts say the gesture is symbolic and that Ukraine is trying to show support for Georgia and move closer to the West in choosing alliances and overseeing its security.
A ministry statement said that because Russia pulled out of the agreement earlier this year, it allowed Ukraine to co-operate with other countries.
"The fact that Ukraine is no longer a party to the ... 1992 agreement allows it to launch active co-operation with European countries to integrate its stations with ... governments with an interest in receiving data of the situation in space," it said.
Viktor Yushchenko, Ukraine's president, issued a decree this week putting an end to Ukraine's participation in the 1992 accord with Russia.
Ukraine's pro-Western leadership, brought to power by "Orange Revolution" protests in 2004 and committed to securing Nato membership, has been increasingly at odds with Russia on a range of foreign policy issues.
Yushchenko has been critical of Russia's position in its conflict with Georgia over South Ossetia.
A presidential decree this week obliged commanders of Russia's Black Sea fleet, based in Ukraine's Crimea peninsula, to seek permission before moving warships and aircraft.
Moscow denounced the move as "anti-Russian" and said its commanders would disregard the order as its forces answered solely to the Russian president.