Nato said yesterday that it has sighted Russian troops and heavy weapons entering Ukraine, while the government in Kiev said that it was again preparing for war in the country’s east.

The United Nations warned of the possibility of a return to “full-scale fighting”.

Nato reported seeing columns of Russian tanks, artillery and air defence systems and Russian combat troops entering Ukraine, Nato’s supreme allied commander Europe, General Philip Breedlove ( left ), said in Sofia, the Bulgarian capital, according to an emailed transcript.

Breedlove said that during the last two days, Nato has “seen the same thing that the Organisation for Security and Co-operation in Europe (OSCE) is reporting”.

The OSCE has said that its observers spotted large-scale troop movements in the region. It has not identified, however, the origin of the convoys.

A Russian Defence Ministry spokesperson quickly rejected the claim as baseless.

“We have stressed many times that the regular hot air from Brussels is not backed by facts,” ministry spokesperson Igor Konashenkov said in Moscow.

Russian Defence Minister Sergei Shoigu accused Nato of feeding anti-Russian sentiments and said that growing tensions have forced Moscow to boost its military presence in Crimea.

“One of our main tasks is to form fully fledged and sustainable joint forces on Crimea,” Shoigu told a meeting of defence officials, according to Russian news agencies.

Russia’s annexation of the Black Sea peninsula in March started the current crisis between Moscow and the West.

Separatists denied that they possess Russian weapons and assured that they were not preparing to attack.

“We signed the peace accords which we obey, whether we like it or not,” Eduard Basurin, a senior militia commander in Donetsk, told Russia’s Ria Novosti news agency.

Ukrainian Defence Minister Stepan Poltorak told a cabinet meeting in Kiev that the armed forces’ main task is “to prepare for combat” as the pro-Russian insurgents are massing troops, according to local  media reports.

Ukraine’s National Security Council said separatists and Russian regular forces continued the military build-up in the eastern districts they control.

Prime Minister Arseniy Yatsenyuk assured that Ukraine was doing everything it could to de-escalate the situation.

“I do not want the world to suffer from colour blindness - the red line has been crossed - not dozens, but hundreds of times,” he said at the same meeting.

Russian Foreign Minister Sergei Lavrov reiterated Moscow’s demand for a “stable and direct dialogue” between Kiev and the separatists.

US ‘deeply concerned’

In New York, Jens Anders Toyberg-Frandzen, the UN Assistant Secretary-General for political affairs, told the UN Security Council: “We are deeply concerned by the possibility of a return to

full-scale fighting.”

The US ambassador to the UN, Samantha Power, accused Moscow of “fuelling war”. Her Lithuanian counterpart, Raimonda Murmokaite, warned that “an undeclared creeping war is being conducted by Russia against Ukraine”.

Ukrainian President Petro Poroshenko told German Chancellor Angela Merkel in a telephone call late Tuesday that the inflow of troops and heavy weapons was evidence that Russia and the separatists have abandoned the Minsk accords.

Merkel assured that the conflict in Ukraine will be a main issue at the G20 summit this weekend in Australia, Poroshenko’s office said.

US President Barack Obama and Russian President Vladimir Putin will attend the summit in Brisbane.

The European Union, the United States and countries like Australia and Japan have imposed sanctions on Russia because of its support for the separatists.

Merkel said that the EU should agree next Monday to add more individuals to its blacklist, but that the bloc should not impose wider economic sanctions against Russia.

US State Department spokesperson Jen Psaki said in Washington she had no new sanctions to announce, new names could possibly be added to the list of Russians under sanction.

“Obviously our preference would be to see a ceasefire continue,” Psaki said. “And what we’ve seen is ... ongoing, continuous, blatant violations of the Minsk Protocol by Russia and its proxies.”

- dpa