"We are in touch with the government," spokesman Richard Boucher said.
He said Washington was also in touch with regional leaders about the situation, which would likely be discussed in a meeting next week of the Organization of American States.
"We've stuck with talking to the government about the security situation, about the situation as regards democracy and maintaining the democracy in Bolivia," Boucher added.
Earlier Wednesday, Bolivian police arrested protesters opposed to government plans to nationalize gas resources who were trying to enter the Government Palace in La Paz, El Universal reported.
Police used tear gas to disperse the thousands, mostly coca leaf growers.
The protests forced the country's lawmakers to abandon a key session of Congress, the BBC reported Wednesday. President Carlos Mesa called the protesters a "small minority" of the population in their opposition to nationalizing gas resources.
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