The stock market's rally on Russian President Vladimir Putin's promise not to go beyond Crimea is not warranted, a leading money manager told CNBC on Tuesday.

"The futures are telling us that in the short term, the markets want to believe Putin," said Jack De Gan, Harbor Advisory's chief investment officer. "But I think you have to judge him by his actions, not by his words."

In a "Squawk Box" interview, De Gan said the manner in which Putin seized Crimea raises doubt. "I believe [Putin] would like to have the rest of Ukraine. But I think he'll let the international furor die down and integrate Crimea first and then look at moving further west."

In a speech before Russia's parliament Tuesday, Putin accused the West of encouraging unrest in Ukraine in order to break its historic ties with Russia. He dismissed criticism from the U.S. and Europe that Sunday's Crimean vote to join Russia was illegitimate. Putin also said he had no reason to push further west. After his address, he signed a treaty to incorporate Crimea into Russia.

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