Ukraine's European neighbors took action to prevent the fast-moving flu from spreading outside the country, where the Ukrainian Health Ministry reported at least 174 deaths and more than 1 million infections due to acute respiratory illness as of Tuesday.
The World Health Organization (WHO) assumes the majority are swine flu cases, according to a statement.
Slovakia, which reported its first swine flu death on Friday, announced it would close most road crossings in the east along its shared border with Ukraine, while Russia plans to examine people entering the country from Ukraine at checkpoints along its western border.