Brussels  - Russian gas monopolist Gazprom refused on Thursday to renew gas supplies to Europe in return for a mission of European Union experts intended to monitor gas flows from the country through Ukraine, EU officials said.

"Gazprom said no to the mission. We are disappointed, because we believe the Russian side has no reason to refuse and not to allow the resumption of supplies through Ukraine to the EU," Czech energy minister Martin Riman, whose country holds the EU's rotating presidency, told reporters in Brussels.

Prague  - The European Union Thursday repeated its call for an immediate ceasefire in the Middle East after a UN driver bringing aid to Gaza was killed in Israeli fire.

"This is another gruesome incident after a UN-administered school was hit," Czech Foreign Minister Karel Schwarzenberg, whose country chairs the EU until June 30, said in a statement.

"We are repeating our call: it is impossible to delay a ceasefire," he said.

Brussels/Prague - Ukraine and Russia remained at loggerheads Thursday over the deployment of international experts to monitor gas flows through Ukraine, European Union officials said.

While both sides have agreed that international monitors could play a role in solving the standoff which has crippled gas supplies to Europe, officials said that no final agreement on a mission had been reached during talks in Brussels.

Prague - The European Union sees a "reasonable" chance for Russian natural gas to soon resume flowing via Ukraine to the 27- member bloc, a Czech official said Thursday.

"I think we can have some reasonable hope in a quick resolution for what is the most urgent need and that is to resume the gas flows," said Czech Vice-Premier for European Affairs Alexandr Vondra before a meeting of EU foreign ministers.

The Czech Republic presides over the EU until June 30.

Washington  - Russia's decision to cut off gas supplies to Europe because of a contract dispute with Ukraine is "unacceptable," the US State Department said Wednesday.

Russian Prime Minister Vladimir Putin green-lighted a full stop of natural gas shipments to Europe through Ukraine, causing shortages on the continent at a time when heating demands increase to counter the chilly winter season.

"Cutting off these supplies during winter to vulnerable populations is just something that is unacceptable to us," State Department deputy spokesman Robert Wood said.

Prague - Greenpeace activists Wednesday briefly flew an EU flag at the Czech president's official Prague Castle residence, where current occupant President Vaclav Klaus has been refusing to do so.

An activist partially climbed a flagpole and unfurled the flag for about 10 minutes shortly before Klaus, an outspoken EU critic, hosted the bloc's executive, the European Commission.