Gate was using the meeting to underscore the importance of international assistance for Afghanistan, where violence remains high despite some success this year in blunting a planned Taliban offensive.
Gates has been pushing for more help in Afghanistan from European countries, not only those in the NATO alliance but others with security and other resources that could contribute to stabilizing the country.
Slovak officials told Gates during a conference of southeast European defense ministers that they will send at least 47 more troops to Uruzgan province in southern Afghanistan, where they will work with Dutch forces, Pentagon press secretary Geoff Morrell said. That will increase its troop total in Afghanistan to 125 next year, he said.
Slovakia also will send eight doctors to work at a military hospital in Kabul, the Afghan capital, Morrell said.
After the meeting Gates was headed to the Czech Republic for talks on the U.S. proposal to install a missile-tracking radar there as part of a Europe-based U.S. missile defense system that is strongly opposed by Russia.
Later this week Gates is scheduled to attend a meeting of NATO defense ministers in the Netherlands, where Afghanistan is expected to be a central focus of talks.
Much of the higher levels of violence in Afghanistan has been in the southern and eastern provinces. The insurgents are increasingly using Iraq-style tactics, such as roadside bombs, suicide attacks and kidnappings to hit foreign and Afghan targets around the country.