WRAPUP 9-EU calls crisis talks as Russian gas flow dwindles

* Russia says Ukraine not delivering all gas to Europe

* EU calls special talks, says deals must be honoured

* Hungary, Poland, Romania say deliveries have dropped

* Ukraine denies siphoning off gas

By Dmitry Zhdannikov and Sabina Zawadzki

MOSCOW/KIEV, Jan 2 (Reuters) - European countries began to suffer from reduced gas supplies on Friday after Russia cut deliveries to Ukraine in a contract dispute.

The Czech Presidency of the European Union said it would call a crisis meeting of envoys in Brussels on Monday and demanded that existing gas supply deals be honoured.

"We feel that the situation has now escalated to a point that substantiates an extraordinary meeting," Czech presidency spokesman Radek Honzak said. Talks would also probably be called soon with Moscow, another spokesman said.