This article is more than 6 years old

This article is more than 6 years old

Ukraine's prime minister Arseniy Yatsenyuk has accused Russia of demonstrating unacceptable "military aggression" which has "no reason and no grounds".

Moscow has deployed 10,000 troops along its border with Ukraine, deepening the crisis in Crimea ahead of a last desperate effort by the US secretary of state, John Kerry, to broker a deal with his Russian counterpart, Sergei Lavrov, in London on Friday.

Yatsenyuk told the UN security council on Thursday he is convinced Russians do not want war. He urged Russia's leaders to heed the people's wishes and return to dialogue with Ukraine. "If we start real talks with Russia, I believe we can be real partners," Yatsenyuk said.

He said Ukraine gave up the world's third-largest nuclear arsenal in 1994 in exchange for guarantees of its independence and territorial integrity. After Russia's recent actions, Yatsenyuk said, "it would be difficult to convince anyone on the globe not to have nuclear weapons".

Russia's UN ambassador Vitaly Churkin said: "Russia does not want war and neither do the Russians, and I'm convinced the Ukrainians don't want that either."

Churkin criticised the "illegal" and "forceful overthrow" of Viktor Yanukovych and asked why a European-mediated plan signed by Yanukovych and Ukraine's protest leaders to form a new government and hold an early election was not seized upon and implemented. Russia refused to sign the agreement but now supports it.

"Instead of a government of national unity as provided for in the 21 February agreement," Churkin said, "in Kiev what you had was a government of the victors."

Russian troops now control the Crimean peninsula, where voters will decide on Sunday whether to become part of Russia.

Western diplomats have expressed little optimism ahead of the London talks. Nothing resembling a peace plan has been sketched out between the two sides, one said.

Kerry warned on Thursday that Russia could face "a series of serious steps". Both the US and the EU say that if the referendum – which they have declared illegal – goes ahead, Moscow will face the prospect of fresh sanctions being imposed.

Russian troop deployments were spotted along the Ukrainian border on Wednesday but Russia initially refused to confirm their presence. The defence minister announced on Thursday that 8,500 troops, along with armoured vehicles, helicopters and artillery, had been ordered to several border regions. In addition, 1,500 paratroopers are to be dropped into the Rostov region near the border.

The defence ministry claimed the troops were only involved in a training exercise that would last two weeks. The ministry said: "The main goal of the ongoing events is to comprehensively assess the units' teamwork and subsequently tackle combat training tasks on an unfamiliar terrain and untested training ranges."

The Russian deployment coincided with a vote in the Ukrainian parliament to create a 60,000-strong national guard. Ukraine's national security chief, Andriy Parubiy, said the force would "ensure state security, defend the borders and eliminate terrorist groups".

US state department spokeswoman Jen Psaki said Kerry would reaffirm US support for Ukrainian sovereignty and territorial integrity without interference or provocation by Russia. The secretary of state had previously declined a Russian invitation to Moscow and his decision to go to London prompted speculation the Kremlin may have offered concessions to ensure he would not leave empty-handed. Other diplomats expressed scepticism.

Kerry and Lavrov spoke by phone on Thursday, and Russia said the two discussed "taking into account existing Russian and US proposals to normalise the atmosphere and provide for civil peace".

Before leaving Washington for London, Kerry warned Russia that the EU was planning to join the US in imposing more sanctions on Moscow if the referendum went ahead. The sanctions would include a travel ban and a freeze on bank accounts.

German chancellor Angela Merkel, backing up Kerry in the strongest language she has employed so far, told the Bundestag that the consequences for Russia would be huge if it failed to enter into negotiations. She ruled out military force. bBut warned sternly that the crisis would cause "massive damage to Russia, economically and politically".

Reuters reported that the German vice-chancellor, Sigmar Gabriel, warned that Germany would not hesitate to go beyond a second round of European sanctions planned for Monday if the referendum goes ahead.

David Cameron and foreign secretary William Hague will meet Kerry before his meeting with Lavrov. A Foreign Office spokesman said Hague had phoned both Kerry and Lavrov to encourage them "to hold talks in London with a view to de-escalating the situation in Crimea and setting up dialogue between Russia and Ukraine".

As part of a series of moves aimed at displaying solidarity with Ukraine, Nato was planning on Fridayto meet representatives of the Tatar population in the Crimea who are largely hostile to a Russian takeover.

Nato's deputy secretary general, Alexander Vershbow, will meet with the Ukrainian MP and leader of the Crimean Tatars, Mustafa Cemilev Kirimoglu.

One person was killed and several were treated for injuries on Thursday evening, when hundreds of pro and anti Moscow demonstrators clashed in the eastern city of Donetsk.

• This article was amended on 14 March 2014. The earlier version referred to Reichstag where Bundestag was meant.