“We haven’t got a common vision in terms of practical steps that foreign countries – Ukraine’s foreign partners – could take. But the talks were certainly helpful to get a better idea of how well we understand each other in the present situation,” Lavrov said.

Kerry did not threaten Moscow with any sanctions over Ukraine, the minister said following six hours of talks with him in London.

Russia’s partners understand that sanctions would be counterproductive, he added.

Russia has not and “cannot have” any plans to invade southeastern regions of Ukraine, Lavrov told reporters.

In Moscow’s view, “the rights of Russians, Hungarians, Bulgarians and Ukrainians must be observed and protected,” he said.

“Our partners also understand that sanctions are a counterproductive instrument. If such a decision is made in Western capitals, it would be their decision,” Lavrov said.

“But that certainly would not be for the benefit of mutual interests, and for the development of our partnership.”

Speaking about the Western-backed idea to set up an international contact group to find a solution to the Ukrainian political crisis, Lavrov said that Moscow disagrees with its proposed format.

As suggested by Western partners, the goal of such a group would be the promotion of “a direct dialogue between Moscow and Kiev.”

“We believe that it is a clear substitution of notions, since the crisis was not the fault of the Russian Federation,” Lavrov said.

John Kerry in his turn reiterated Washington’s stance on the upcoming March 16 referendum, saying that the US views it as illegitimate and that neither the US nor the international community will recognize the outcome of the vote.

The US is also concerned about “Russia’s presence in Crimea and along the Ukrainian border,” Kerry said.

The US would want to see Russian troops “moving in the opposite direction,” and diminishing in number, he said.

Washington will ask President Putin “to pull back” Russian troops to bases and freeze any moves to give diplomacy a chance to work, Kerry said.

If the Crimean population decides in the referendum to join Russia, it would be "backdoor annexation" of the republic, Kerry said.

He added that he did not know definitely what Putin would decide after the vote.

Kerry said the issue of additional autonomy for Crimea has always been on the table, and it is up to the Ukrainian government to decide.

He also reiterated that would be “consequences” and “costs” for Russia over the situation in Ukraine.

The tensions have particularly intensified as Crimea readies to hold a referendum on whether the autonomous republic wants to remain part of Ukraine, or to join Russia.

After more than three hours, @JohnKerry and #Russia's FM Lavrov continue talks on de-escalating tensions in Ukraine. pic.twitter.com/ru9QC5DhPe

— Department of State (@StateDept) March 14, 2014

The republic, which has an ethnic Russian majority, is holding a historic vote Sunday.

Ahead of the meeting with Kerry, Lavrov spoke with UK Prime Minister David Cameron and Foreign Minister William Hague.

Cameron said Britain wanted to see progress and "Ukrainians and the Russians talking to each other and if they don't, then there are going to have to be consequences."

He added that “the alignment of Britain and the European Union with the position that the US is taking is absolutely right. We must keep at them."