Russia is continuing to send troops to what is now the biggest concentration of forces in Europe since the cold war, contradicting Moscow’s claims of a drawdown on Ukraine’s border, Nato’s secretary general has said. Despite suggestions from Russia’s president, Vladimir Putin, that a “partial” withdrawal was in effect, Jens Stoltenberg said Russian military capability was only increasing in number and strength. In a warning shot to the Kremlin, Stoltenberg, a former prime minister of Norway, announced that the military alliance was considering deploying further battle groups in eastern and central Europe. They would complement those established in 2014 in Estonia, Latvia, Lithuania and Poland, led by the UK, Canada, Germany and the US. The French government has offered to lead a force in Romania. “We will have advice from the military commanders within weeks and we will make a decision after that,” Stoltenberg said during a break in talks between Nato defence ministers in Brussels. “What we see today is that Russia maintains a massive invasion force ready to attack with high end capabilities from Crimea to Belarus. This is the biggest concentration of forces in Europe since the cold war.” The British defence secretary, Ben Wallace, said the UK was doubling the number of personnel in Estonia and sending additional equipment, including tanks and armoured fighting vehicles. Four additional UK Typhoon jets landed in Cyprus on Wednesday in order to patrol the skies of eastern Europe. In reference to a series of cyber-attacks that have knocked the websites of the Ukrainian army, the defence ministry and major banks offline, Stoltenberg told reporters: “What we see is that Russian troops are moving into position and we saw the cyber-attack. And these are the kinds of actions and measures that we expect will come in advance or bigger military intervention into Ukraine.” The potential deployment of further battlegroups risks antagonising Putin but the alliance is seeking to emphasise to Russia that its aggression will only lead to a larger Nato presence to its west. Stoltenberg said Nato was “prepared for the worst” while holding out hope that the signalling from Putin in recent days was evidence of a sincere desire to find a diplomatic way through the crisis. He said: “So far we have not seen any de-escalation on the ground. On the contrary, it appears that Russia continues the military buildup. “What we see is that they have increased the number of troops and more troops are on their way and so, so far, no de-escalation.” Stoltenberg said the evidence on the ground “contradicts the message of real diplomatic efforts”, and warned that Russia’s attempted leveraging of military force to force countries to acquiesce to its demands should be seen as the “new normal”. US secretary of state Antony Blinken echoed Stoltenberg’s analysis, as the White House backed a formal demand at the OSCE’s Forum for Security Co-operation from Latvia, Lithuania and Estonia for Belarus to provide firm details within 48 hours of the scale of the Russian military force on its territory. “Unfortunately there’s a difference between what Russia says and what it does, and what we’re seeing is no meaningful pullback,” Blinken said. “On the contrary, we continue to see forces, especially forces that would be in the vanguard of any renewed aggression against Ukraine, continuing to be at the border, to mass at the border.” In a rare public statement, the UK defence intelligence chief, Jim Hockenhull, added that he had “not seen evidence” of a drawdown in Russian troops. “Russia has the military mass in place to conduct an invasion of Ukraine,” said Hockenhull. During a press conference with the German chancellor, Olaf Scholz, in Moscow on Tuesday, Putin had told reporters that he was undertaking “a partial withdrawal of troops from the areas of our exercises”. On Wednesday, the Russian defence ministry released footage on its Zvezda television channel reportedly showing tanks, armoured personnel carriers and mobile artillery elements of the 42nd motorised rifle division crossing the Crimean Bridge and heading away from the peninsular. Izvestia, a Russian newspaper with sources in the defence ministry, reported that the units returning to their bases were the 3rd, 42nd, and 150th motorised rifle divisions. Analysts noted, however, that two of the three of those divisions are stationed very close to Ukraine. The 3rd motorised rifle division has permanent bases to the north-east of Ukraine while the 150th motorised rifle division is garrisoned near Rostov-on-Don, just to Ukraine’s south-east. Just the 42nd motorised rifle division would be taking a longer trip back to Chechnya, if the units return to their permanent bases. Russia’s foreign ministry spokesperson, Maria Zakharova, dismissed the claims of reinforcements. She said: “Frankly, I can tell you the truth. We’re not interested in these statements made by Stoltenberg, who is either Nato secretary general or a banker, I haven’t figured out which yet. We’re no longer interested in them. He is not a person whose statements Moscow would consider serious arguments. He is a Nato has-been now.” Stoltenberg is to leave Nato at the end of September, becoming chief of the Norwegian central bank in December. The US president, Joe Biden, said in an address on Tuesday that he believed that more than 150,000 Russian troops remained near Ukraine’s borders, more than 60% of the country’s ground forces. Stoltenberg would not give a definitive number with regard to the size of the Russian presence on Wednesday, noting that the Kremlin pulled troops back and forth over time. “We are seeing that it goes up and up and up – and it continues to increase,” he said. “Of course, what we’ve seen several times over the last months is that they move in with a high number of troops and heavy equipment. Then they take most of the troops out again but the equipment stays. Then they can very easily, very quickly, send the personnel back again and they are operating up with all the capabilities in place.” He added: “It is not too late for Russia to step back from the brink of conflict and choose the path of peace. Nato has sent concrete written proposals to Russia on transparency, risk reduction and arms control. We have yet to receive a response. I reiterate my invitation to Russia to meet again in the Nato-Russia Council.” In Strasbourg, the European Commission president, Ursula von der Leyen, told that EU was ready for the fallout of conflict, including a reduction in gas supply, as alternatives had been negotiated and that Europe was “now on the safe side of winter”.