Sofia - Bulgarian Prime Minister Sergey Stanishev left Wednesday for a one-day trip to Moscow and Kiev and urgent talks about the Russian-Ukrainian gas row which has shoved much of the Balkans into a deep crisis.

In Moscow, Stanishev was due to meet both Prime Minister Vladimir Putin and President Dmitry Medvedev and the management of the Russian Gazprom, his cabinet said in Sofia.

Stanishev would then fly to Kiev, for talks with Ukrainian President Victor Yushchenko and Premier Yulia Timoshenko.

Bulgaria, which acquires all but a tiny fragment of the gas it uses from Russia via Ukraine, was hit hard when Moscow switched the taps off last week accusing Kiev of stealing gas in transit to Europe.

Despite an agreement the European Union pushed through on Monday, which includes sending international and Russian observers to monitor the flow of gas through Ukraine, supplies were again blocked shortly after they were resumed on Tuesday.

A group of Bulgarian experts assigned to join the monitoring mission were on Stanishev's flight on Wednesday.

Since the crisis erupted, gas-dependent Bulgarian companies have built up 101 million leva, or nearly 70 million dollars, in losses. (dpa)