MOSCOW — President Putin yesterday named a prominent nationalist politician as Russia’s ambassador to NATO at a time of severely strained ties between Moscow and the Western alliance.

The appointment of the outspoken nationalist, Dmitry Rogozin, is the latest reflection of Mr. Putin’s assertive stance toward the West, which he accuses of meddling in Russia’s affairs and says must treat Moscow as an equal.

But while it may place a stronger spotlight on Russia’s wrangling with NATO, it did not appear to signal a shift in Russian policy toward its former Cold War foe.

Mr. Rogozin, a former member of Parliament who headed a nationalist party, replaces General Konstantin Totsky.

Mr. Putin, who has courted support at home and around the globe by lashing out publicly at the West, “wanted to emphasize Russia’s negative attitude toward what NATO is doing,” the editor of Russia in Global Affairs magazine, Fyodor Lukyanov, said. “But I don’t think it will have a significant effect on relations between Russia and NATO.”

Meanwhile, Polish and Russian officials yesterday held high-level talks on the American plan to build a missile defense base in Poland, while the Czech prime minister said his government could finalize a deal on its part of the project as soon as April.

Poland’s new government appears cooler toward the plan than its predecessor, and Prime Minister Tusk refused during a visit to Prague yesterday to put a timeline on a possible deal.

Mr. Tusk’s government has vowed to consult with Russia on the American proposal to place 10 interceptor missiles in Poland, which Moscow says would pose a threat to its security. The plan also calls for a radar base in the Czech Republic. In Warsaw, Poland’s chief missile defense negotiator, Witold Waszczykowski, and Deputy Foreign Minister Sergei Kislyak of Russia exchanged views, and discussed how to counter current and emerging threats.