Russian president Vladimir Putin has accused the US of attempting to "subdue" Russia in a speech in Moscow, and added that the US wants to solve its problems at Russia's expense.

Putin told the All-Russia People's Front: "They (United States) do not want to humiliate us, they want to subdue us, solve their problems at our expense."

"No one in history ever managed to achieve this with Russia, and no one ever will," Reuters reported.

The speech comes amidst escalating tension between Russia and the West, with US and the EU accusing the Kremlin of fuelling unrest in east Ukraine by supplying weapons and military equipment to separatists, a charge Moscow denies.

In an interview with German TV, details of which emerged today, Putin also claimed that successive Nato expansion in eastern and central Europe had been "significant geopolitical game changers" that Russia had been forced to respond to.

"Nato and the United States have military bases scattered all over the globe, including in areas close to our borders, and their number is growing," Putin told the German ARD channel. "Moreover, just recently it was decided to deploy special operations forces, again in close proximity to our borders. You have mentioned various [Russian] exercises, flights, ship movements and so on. Is all of this going on? Yes, it is indeed."

Earlier, Nato's Secretary-General Jens Stoltenberg said that Russia was responsible for a build-up of weapons and military equipment on the Russian side of the border with Ukraine, and in Ukraine itself, and urged them to pull back troops.

Kiev said that six Ukrainian soldiers died in fighting in east Ukraine in the past 24 hours, where separatists are attempting to form a breakaway pro-Russian republic.

It brings the number killed in fighting in the region since a ceasefire was declared on September 5 to 140.