MOSCOW — President Putin vowed yesterday to strengthen Russia’s military capability and step up spying abroad in response to American plans to build missile defense sites and deploy troops in Eastern Europe.

“The situation in the world and internal political interests require the Foreign Intelligence Service [a successor agency to the KGB] to permanently increase its capabilities, primarily in the field of information and analytical support for the country’s leadership,” Mr. Putin said at a meeting with senior military and security officers in remarks that were posted on the Kremlin’s Web site. Mr. Putin did not identify specific nations as targets, but officials in America and Britain have said recently that Moscow has intensified its spying in those countries.