Russian gas monopoly Gazprom on Tuesday reduced gas supplies to Belarus by 30 percent of the planned volume from 10 a.m. Moscow time (0600 GMT), said the company's CEO Alexei Miller in televised comments.

Miller said Gazprom continued to reduce supplies because Minsk failed to take any measures during the past 24 hours to settle its debt of 200 million U.S. dollars.

On Monday, Gazprom cut gas flow to Belarus by 15 percent by the order of Russian President Dmitry Medvedev.

Later in the day Belarusian Deputy Prime Minister Vladimir Semashko promised to pay its debt within two weeks.

Gazprom spokesman Sergei Kupriyanov also told Russian media on Monday that the gas transits to Europe will remain unaffected. Belarus is a transit country for part of Russian gas exports to Europe.

Ensuing the further gas cut, Kupriyanov on Tuesday told reporters that Belarus has threatened to siphon off gas from the pipeline.

"We received a letter from Belarusian Deputy Prime Minister Vladimir Semashko, which does not contain any specific answers to our questions. The letter ends with a threat in the event of further reduction in gas supply to Belarus to take action to take gas (out of the pipeline) in order to meet the needs of Belarusian consumers," said the spokesman.

The delegation from Minsk that came to Moscow for consultations over the debt issue on Monday has flown back, without giving "any coherent answers to our questions about settling the gas debt," added Kupriyanov.

The deputy CEO of Gazprom, Alexander Medvedev, meanwhile assured that the company was ready to jointly monitor transit route across Belarus with European observers, "to assess who is doing what and who is violating what."

"We will do everything we can to ensure that our European consumers are not affected," said Medvedev.

According to Minsk, the 200-million-dollar gas debt is equal to the transit debt owed by Gazprom and thus could be offset.

The latest gas dispute has become a reminder of the early 2009 row between Moscow and Kiev that left some European countries heatless in the depths of winter.