U.S. Defense Secretary Robert Gates has asked eastern European allies to send more troops to Afghanistan.

Gates told a meeting of the Southeastern Europe Defense Ministerial in Budapest, Hungary, that they have what he called an "important role" in ensuring peace and stability around the globe.

All countries in the Southeastern Defense group but one, Bosnia-Herzegovina, currently have troops stationed in Afghanistan. But Gates told the ministers they should shift more resources there, since the situation in Iraq has improved.

Earlier, Gates met with his Ukrainian counterpart, Yuri Yekhanurov and pledged U.S. support for Ukraine to join NATO, despite political unrest brewing in that country.

Gates said the United States is ready to work with whatever coalition results from the current political situation in Ukraine.

Gates is set to attend an informal meeting of NATO defense officials in the Hungarian capital, Budapest, on Thursday and Friday. Regional power Russia has resisted the eastward expansion of the alliance.

Along with Ukraine, Macedonia also is vying for NATO membership, but alliance member Greece has blocked Macedonia's bid because Macedonia shares its name with a Greek province.