KYIV, Dec 3 - Ukraine's president on Monday announced a partial call-up of reservists for training amid tensions with Russia, saying the country needs to beef up its defenses to counter the threat of a Russian invasion.

The Kremlin dismissed the Ukrainian leader's statement as an "absurd" attempt to inflame tensions, The Associated Press reported.

Relations between the two neighbors have been strained further following a Nov. 25 incident in which the Russian coast guard fired upon and seized three Ukrainian naval vessels and their crews off the Crimean Peninsula that Russia annexed from Ukraine.

President Petro Poroshenko responded by introducing martial law for 30 days in much of Ukraine. For the duration of martial law, Ukrainian authorities barred entry to all Russian males aged 16 to 60 in a move the Ukrainian leader said was needed to prevent Russia from further destabilizing the country.

Poroshenko said Monday that some reservists will be summoned for training as part of martial law. He also said that some military units will be redeployed to strengthen the nation's defenses.

"Ukraine is taking its own steps in response to the threat of a large-scale Russian invasion," Poroshenko said.

Over the weekend, Poroshenko said that Russia has deployed a large number of troops along its border with Ukraine and alleged that the Kremlin intends to push inland into Ukraine. Ukraine also accused Russia of blockading its ports on the Sea of Azov.

Russian President Vladimir Putin's spokesman, Dmitry Peskov, dismissed Poroshenko's claims as an "absurd attempt to foment tensions."

"The accusations against Russia have no basis whatsoever," he said.

Peskov also rejected Kiev's claim that Russia was blocking traffic to and from Ukrainian ports on the Sea of Azov, saying that navigation has continued normally except for occasional breaks because of bad weather.

Over the weekend, Poroshenko urged Germany and other Western allies to boost their naval presence in the Black Sea to help deter Russia from further aggression.

Ukraine's deputy defense minister, Anatoliy Petrenko, said the country is talking to its Western partners to respond to Russia's "escalatory actions." (ap/ez)