The United States said on Wednesday it was prepared to help Kyrgyzstan's new rulers, putting pressure on ousted president Kurmanbek Bakiyev, who hinted he may go into exile. The unrest has disrupted flights from the Kyrgyz air base that the United States rents to support the war in Afghanistan. Russian President Dmitry Medvedev has warned that the poor Central Asian country may be on the brink of civil war. “I feel optimistic about the steps (the interim government) is already taking ... the United States is prepared to help,” US Assistant Secretary of State Robert Blake told reporters after meeting interim government head Roza Otunbayeva. Otunbayeva said she and Blake did not discuss the US air base. Blake is the most senior US official to visit Kyrgyzstan since Bakiyev's opponents took power after an April 7 uprising, during which troops repeatedly fired into crowds of opposition protesters in the capital. At least 84 people were killed and another 1,600 were injured. Otunbayeva called for Bakiyev to be put on trial for the deaths in the unrest. “If we get our hands on Bakiyev, then he will be put on trial,” she told reporters after meeting Blake. “He has already had his chance to leave.” Bakiyev denies giving the order to fire into the crowds, but his brother Dzhanibek Bakiyev, the chief of the presidential bodyguard, has admitted doing so. Washington is concerned the crisis will affect its five-year lease deal with Kyrgyzstan for use of the Manas air base. After last week's upheaval, some members of the interim government had suggested the lease would be shortened to please Moscow. The interim government says it will abide by its agreements, but pro-Russian sympathies of some ministers have given rise to suspicions Kremlin may try to use the base as a lever in its ties with Washington.