President Boris Yeltsin canceled his meetings Friday after doctors said he was suffering from an acute respiratory infection.
The Kremlin press service said Yeltsin, 67, had a sore throat because of the infection and was being treated with antibiotics.Yeltsin was staying at his country home outside Moscow and has not been hospitalized.
A brief statement said Yeltsin was experiencing discomfort in speaking. It said the president had "acute laryngotracheitis," defined in medical dictionaries as an "inflamed condition of the larynx and trachea," but his temperature was normal.
Yeltsin has suffered from heart troubles and other health problems in recent years, raising concerns about his ability to govern.
The president "has a cold, and his voice is a bit hoarse," Yeltsin's chief of staff Valentin Yumashev told a Kremlin meeting of TV officials Friday.
A Kremlin spokesman reached by The Associated Press declined to say how long Yeltsin was expected to be away from work.
First Deputy Premier Anatoly Chubais, speaking to a visiting group of German lawmakers, apologized on Yeltsin's behalf.
"There is some kind of flu epidemic in Russia," he said. "He had hoped to meet you today, but the doctors advised him it would be better not to do so."
On the stock market, reports of Yeltsin's illness sent the Russian Trading System index down nearly 2 percent from Thursday's closing within in early trading, but it quickly rebounded.
"This has happened so many times before. Like a cat, Yeltsin has nine lives," noted Dmitry Tsarenko, equity trader at Regent European Securities Ltd. in Moscow.
The opposition-controlled State Duma, parliament's lower chamber, appeared rather calm.
"Everyone can fall ill. It's simply age," said the Communist speaker of the Duma, Gennady Seleznyov.
Yeltsin had been scheduled to hold meetings in the Kremlin Friday with a delegation of German parliament members and Russia's culture minister, said the president's chief of staff and TV officials.
The president is scheduled to meet with French President Jacques Chirac and German Chancellor Helmut Kohl in Russia in late March.
Yeltsin was shown on Russian television Thursday after meeting with officials and appeared to be relaxed and in good health.
Earlier this week, Yeltsin complained that he faces too much media scrutiny about his health. He said doctors who examined him last week detected no problems.
Yeltsin underwent heart bypass surgery in November 1996 after suffering a heart attack. He came down with pneumonia two months after that surgery.