He said the post-communist countries are particularly vulnerable to Chinese and Russian predatory investment and political meddling.
To combat the threat, he said the United States is committed to boosting its engagement in the region, through defense cooperation agreements and exchange programs.
"I want to make sure that the Slovakian people understand that America is engaged, we're back," he said at a brief ceremony at Slovakia's "Gate of Freedom" a memorial on the banks of the Morava River at the Slovakian border with Austria that commemorates the 400 people killed at the borders of the former Czechoslovakia while attempting to escape the Iron Curtain between 1945 and 1989.
"This relationship was built on shared values and now we must sustain it on those same, especially as Russian aggression undermines freedom on this continent, but also against a China that represses people while it's expanding its influence abroad," he said.
"We must recommit to our values again and again and again generation after generation to ensure that they live on."
Pompeo is in Slovakia on the second leg of a five-nation European tour that began in Hungary and will take him to Poland, Belgium and Iceland.
On Monday in Budapest, Pompeo warned that the United States may be forced to scale back certain operations in Europe and elsewhere if countries continue to do business with Chinese telecommunications company Huawei.
Pompeo said nations would have to consider choosing between Huawei and the United States. The warning was broad but pointedly delivered in Hungary, a NATO ally and European Union member, where Huawei is a major player.
The U.S. has been warning countries about the risks of Chinese telecom technology as governments choose providers for the rollout of "5G" wireless internet, which will enable faster download speeds but also greater connectivity among devices.
Pompeo says the presence of Chinese telecom infrastructure could drive a technological wedge between the U.S. and some allies.
"It also makes it more difficult for America to be present," Pompeo said.
"That is, if that equipment is co-located where we have important American systems, it makes it more difficult for us to partner alongside them.
We want to make sure we identify (to) them the opportunities and the risks with using that equipment." Pompeo raised those concerns with Hungary's nationalist Prime Minister Viktor Orban, who has been criticized for seeking closer ties with Russia and China and for increasingly authoritarian rule at home.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)