MOSCOW, Jan 20 (Reuters) - President Vladimir Putin said on Tuesday Russia must strengthen its armed forces to protect its sovereignty against the "challenge" posed by other countries that might threaten Moscow.

Putin's comments reinforced his commitment to an expensive programme to modernise the armed forces, which the Finance Ministry has signalled will be excluded from any budget cuts forced on the government by a growing economic crisis.

"We will continue to strengthen our armed forces and military organisations as a whole by making them modern, mobile, well-equipped and capable of performing their main task - to neutralise risks and political, potential threats to the security of our country," Putin told a meeting of Russia's industry commission.

Putin identified no specific threats but Russia's new military doctrine says NATO expansion is a threat.

Putin has also accused the United States of trying to subjugate Russia, has blamed the West for the overthrow of a Moscow-backed president in Ukraine last year and has said Washington stoked protests against him three years ago.

"We see how other countries are open about their geopolitical claims, and do not hesitate to interfere openly in the affairs of independent states while actively expanding and improving their military arsenals," Putin said.

"They spend many times more than we spend (on arms). We can and must respond to this challenge," he said.

(Reporting by Darya Korsunskaya, Writing by Thomas Grove, Editing by Timothy Heritage)