Russia accused the Kiev government yesterday of flouting an international agreement meant to diffuse the Ukraine crisis.

"The Geneva accord is not only not being fulfilled, but steps are being taken, primarily by those who seized power in Kiev, that are grossly breaching the agreements," Russian Foreign Minister Sergei Lavrov said.

He was replying to charges from Washington that Moscow is dragging its feet on implementing the accord hammered out last Thursday in Geneva between Russia, Ukraine, the US and the European Union.

Meanwhile, US Vice-President Joe Biden arrived in Kiev in a show of support for its unelected leaders.

He is due to meet interim president Oleksandr Turchynov and prime minister Arseniy Yatsenyuk today.

The pact had already been undermined by a deadly weekend shoot-out on Sunday in which three pro-Russian demonstrators were shot dead by rightwingers.

The deal called for all "illegal armed groups" to surrender their weapons and halt the occupation of public buildings.

Washington has warned Moscow that time is running out for the accord to be put into practice.

But Moscow in turn has cautioned that Ukraine's illegitimate leaders are using force against separatist protesters.

It also wants to see anti-Russian demonstrators in Kiev cease their occupation of the capital's main square in line with the Geneva agreement.

The US and its Nato allies have increased military deployments in eastern Europe.

And Washington and Brussels have pledged billions to shore up the beleaguered Kiev government's tottering economy.