"As long as the teams participating in UEFA competition have enough eligible players and the public authorities in each country have not imposed any contrary restrictions, all the matches must be played on the dates laid down by the competition regulations," said European football's governing body in a statement on Friday.
Ukraine on Friday closed schools, banned all public events and imposed restrictions on people's movements around the country for a three-week period after confirming its first death from H1N1 flu.
World football's governing body FIFA said it was monitoring the situation ahead of next month's World Cup play-off between Ukraine and Greece.
Inter Milan are due to visit Kiev for their Group F match on Wednesday. There are no Europa League matches scheduled for Ukraine next week.
A UEFA spokesman said, however, that either club involved could ask for a postponement and that requests would be judged on a case-by-case basis.
The spokesman added that UEFA had been in touch with Ukrainian authorities.
Ukraine's national side are due to host Greece on November 18 in the second leg of their World Cup qualifying European playoff.
"FIFA closely monitors the development of the situation in the country," said a FIFA statement.
Last week's French league match between Paris St Germain and Olympique Marseille was postponed by the French federation after three PSG players went down with the illness.
Earlier this year, a number of matches in the Mexican championship were played behind closed doors after the outbreak of the disease in that country.
The South American Football Confederation (CSF) refused to allow Mexican sides Guadalajara and San Luis to play their second round Libertadores Cup ties at home to foreign opponents at the height of the crisis.
The Mexican federation pulled their clubs out of the competition - the region's equivalent of the Champions League - in protest.
