DONETSK, Ukraine -- Days before Ukraine's presidential elections, the interim government Wednesday relished what felt like a letup in tensions.

President Vladimir Putin insisted Russian troops have begun moving away from Ukraine's borders, and the nation's wealthiest and arguably most influential businessman made an impassioned appeal for a cessation to unrest in the east.

And yet, armed pro-Russian insurgents in turbulent eastern regions of Ukraine continued to roam with impunity and do their utmost to derail Sunday's decisive vote.

Speaking to reporters at a security summit in Shanghai, Putin said Moscow's decision to de-escalate its military presence near Ukraine was motivated by a desire to see the election proceed smoothly.

Russia's Defence Ministry said its military units in the regions near Ukraine have started moving to railway stations and airfields en route to their home bases, which they are expected to reach before June 1.

But NATO, which estimates that Russia has 40,000 troops along the border with Ukraine, repeated that it didn't yet see any signs of a Russian withdrawal.

"We have heard the third announcement from President Putin of withdrawal of Russian troops and I wake up every morning hoping to see a real and meaningful withdrawal of Russian troops, but I have to tell you that so far we have not seen any visible evidence of a withdrawal of Russian troops," NATO Secretary General Anders Fogh Rasmussen said during a visit to Sarajevo.

In comments broadcast on Russian television, Putin poured scorn on skeptical assertions about troop movements, saying "those who aren't seeing it should look better." He said the pullout will be clearly visible in satellite images.

"The numbers of troops and armour are quite large, and their pullout requires serious preparation. If the weather is good, they will see it all from space," Putin said.

He sought to offset Western pressure by visiting China, where he oversaw the signing of a $400 billion, 30-year deal to export Russian gas to China.

The pullout decision appears to reflect the Kremlin's desire to ease tensions with the West over Ukraine and avoid further sanctions.

Putin warned, however, that it would be "very difficult for us to develop relations with people who come to power amid a punitive operation in southeastern Ukraine."

That was a reference to ongoing efforts by Ukraine's armed forces to crush the armed wing of the self-styled Donetsk People's Republic, which last week declared independence for the region following a contentious referendum. Insurgents in the neighbouring Luhansk region have also claimed independence, but stopped short of requesting annexation by Russia, as rebels did in Donetsk.

Putin said Russia has helped establish a dialogue between the central government in Kyiv and people in the southeast, but didn't give any details.

Many in eastern Ukraine resent the interim authorities in Kyiv that came to power after the toppling of Ukraine's pro-Russian president in the wake of months-long protests. They see the new government as a group of nationalists bent on repressing Russian-speakers.

Moscow supports a peace plan brokered by Switzerland and the Organization for Security and Cooperation in Europe, which envisages a broad amnesty and the launch of a national dialogue that focuses on the decentralization of government and upholding the status of the Russian language.

A third round table under the plan was held Wednesday in the southern city of Mykolaiv.

Speaking at that assembly, Prime Minister Arseniy Yatsenyuk said that he sensed an uptick in stability in the Donbass -- an area that encompasses the Donetsk and Luhansk regions.

"Those that represent Donbass and control Donbass have declared that no self-appointed bandits of the Donetsk Republic will run either Donbass or Ukraine," Yatsenyuk said. "I can attribute this to our collective efforts."

The government has over the past week had its hand in the east strengthened by a sequence of strongly worded statements by metals tycoon Rinat Akhmetov, who owns major industrial assets in Donetsk region.

In an emotive video address, Akhmetov on Wednesday condemned the Donetsk People's Republic as a "bunch of impostors" and vowed they would be "kicked out of here very soon."

"If some of you believe that they are leading us to success, this is a mistake. It is a huge mistake," he said. "They are leading to collapse, poverty and hunger."

Despite increasing bullishness among government officials, the prospects for the election going ahead as hoped in the east Sunday are looking grim. Around one-seventh of Ukraine's 36 million voters live in the regions most wracked by insurgent activity.

Local election commission representatives have reported rampant intimidation from Donetsk People's Republic supporters and openly concede the vote will be called off in many locations.

Valery Dudarenko, deputy head at one local district election commission in Donetsk, said he expected only 60 out the 88 polling stations under his purview to be working Sunday. He said ballot papers had yet to be delivered.

At another election commission office in the city, deputy chairman Irina Kondratenko said her office has received tentative promises of added security.

"We recently had threats and attacks from so-called representatives of the Donetsk People's Republic. We were threatened by people with guns. They came in and took all of our paperwork. And now we are trying to put it back together again," she said.

The Central Election Commission said that 13 out of 34 district election commissions in the Donetsk and Luhansk regions have been seized and that others may succumb to the same fate.

Meanwhile, the Russian government has complained that the Ukrainian government is preventing reporters for Russian outlets from providing coverage of the election. Ukraine has decried Russian media coverage of recent developments as propaganda aimed at inciting turmoil.

Kremlin-owned English language television station RT said a British national working for them was detained Tuesday by the National Guard while on assignment in the southeastern city of Mariupol. RT said Ukrainian authorities have refused to provide any details about why Graham Phillips, 35, was being held.

Security services spokeswoman Marina Ostapenko told The Associated Press on Wednesday that Phillips was being escorted to Kyiv, where he was to be handed over to the British consul.

The detention this week by Ukrainian security services of two correspondents with Moscow-based Life News television has also drawn vocal outrage in Russia. The reporters are accused of aiding armed insurgents -- a claim that Putin has dismissed as "rubbish and nonsense."