Russia's President Vladimir Putin says he hopes he won't have to send Russian troops into eastern Ukraine, which has been engulfed by violent protests against the new authorities in Kiev.

He also rejected claims that Russian special forces are fomenting unrest there but recognised for the first time that the troops in unmarked uniforms who had taken control of Ukraine's Crimea before its annexation by Moscow were Russian soldiers.

He expressed hope for a political and diplomatic solution of the worst East-West crisis since the Cold War.

Speaking in a televised call-in show with the nation, Mr Putin harshly criticised the West for trying to pull Ukraine into its orbit and said that people in eastern Ukraine have risen against the authorities in Kiev, who ignored their rights and legitimate demands.

A wave of protests, which Ukraine and the West said was organised by Russia and involved Russian special forces, have swept eastern Ukraine over the past weeks, with gunmen seizing government offices and police stations in at least 10 cities.

"It's all nonsense, there are no special units, special forces or instructors in the east of Ukraine," Mr Putin said.

At the same time, he recognised for the first time that soldiers in unmarked uniforms - dubbed "little green men" by some - who appeared in Crimea laying the ground for its annexation by Moscow last month were Russian troops.

Mr Putin, who previously said the troops were local self-defence forces, said the Russian soldiers' presence was necessary to protect the local population from armed radicals and to ensure the holding of a referendum, in which an overwhelming majority of its residents voted to join Russia.

"Our servicemen stood behind the back of Crimea's self-defence forces," Mr Putin said. "They acted politely, but resolutely and professionally. There was no other way to hold the referendum in an open, honest and honourable way and allow the people to express their opinion."

Mr Putin insisted that protests in the east of Ukraine only involve locals. He said that he told his Western counterparts that only local residents are involved in the protests in the east, and "they have nowhere else to go, they are masters of their land."

He denounced the Ukrainian authorities' decision to use the military to uproot the protests in the east as a "grave crime".

He expressed hope for the success of today's talks in Geneva that brings together the United States, the European Union, Russia and Ukraine for the first time since the Ukrainian crisis erupted.

Russia has demanded that the new government in Kiev, which replaced the ousted pro-Russian President Viktor Yanukovych who fled to Russia following protests over his decision to ditch a pact with the EU in favour of closer ties with Russia, move to transform the country into a loose federation. Ukraine has rejected the demand, but promised to give the regions more powers.

Mr Putin repeated his argument that regions in eastern Ukraine historically had been part of the Russian empire and called Novorossiya before they were handed over to Ukraine by the Bolsheviks in the 1920s. "God knows why," he said.

But he also seemed to keep the door open for Russia to recognise Ukraine's presidential election set for May 25, softening his previous demand that it must be postponed until the autumn and preceded by a referendum on broader powers for the regions. He added that the primary goal is to ensure that people in the east should be offered clear guarantees of the protection of their rights.

Mr Putin also urged Ukraine to reopen trade and transport routes into Moldova's separatist province of Trans-Dniester. Russia and the Trans-Dniester authorities say that the Ukrainians have blocked transport routes to the region. Moldova has frozen ties with Trans-Dniester since the 1992 war.

Mr Putin maintained a tough stance on the gas price to Ukraine, which Russia has hiked 80% since Mr Yanukovych's ousting and warned that Moscow will start requesting advance payments for gas shipped to Ukraine in one month if it fails to reach agreement on settling its debts.

Facing questions about more Western penalties to follow the first rounds of sanctions over the annexation of Crimea, Mr Putin sought to assuage fears they could cripple Russia's vital energy sector. He said that the EU will be unable to do without Russian natural gas supplies, and it would be hard for the U. to hurt Russia by encouraging a drop in oil prices.

"They badly want to bite us, but their opportunities are limited," he said.

He also took a video question from National Security Agency leaker Edward Snowden, whom Russia granted asylum last year.

Asked by Mr Snowden about Russia's surveillance programmes, Mr Putin said that Russian special services also tap on communications in their fight against terrorism, but don't do it on such a massive scale as the US.