The US and Russian foreign ministers will hold talks in Geneva on Friday in a development that a US official said suggested that “perhaps diplomacy is not dead” in the efforts to fend off a new Russian attack on Ukraine. With the White House warning that such an attack could come “at any time”, the US secretary of state, Tony Blinken, will fly to Kyiv on Wednesday and Berlin on Thursday to consult with the Ukrainian government and European allies before the meeting the Russian foreign minister, Sergei Lavrov. It comes as Nato also offered Russia a fresh round of talks. “The fact that Secretary Blinken and Foreign Minister Lavrov agreed to meet on Friday in Geneva suggests that perhaps diplomacy is not dead,” a senior state department official said. “We will certainly know a lot more after that engagement on Friday.” At the end of last week, after three sets of discussions in Europe that produced no progress, a senior Russian official suggested that diplomacy could be at a dead-end. Since then tensions have continued to rise, with movements of Russian troops and heavy weapons westwards from the far east, and into Belarus. “We’re now at a stage where Russia at any time could launch an attack on Ukraine,” said the White House spokeswoman, Jen Psaki. Nato was not notified of the Russian military exercises in Belarus, a US official said, noting that the troops were in “numbers beyond what we’d expect in regard to a normal exercise”. “What it represents is an increased capability for Russia to launch this attack – increased opportunity, increased avenues, increased routes,” the official said, questioning how much control Belarus leader Alexander Lukashenko – weakened by popular opposition to his rule – had over events. “The question is: Where do their authorities at this point end and where do the Kremlin’s begin? And that is very uncertain.” “Russian military plans to begin activities several weeks before a military invasion is something we’ve been watching closely and our assessment has been that could happen anytime between mid-January and mid-February,” a senior state department official said. On Tuesday, the Nato secretary general, Jens Stoltenberg, echoed US claims that there was a “significant Russian presence of intelligence operatives inside Ukraine” and that it was “absolutely possible” they were planning “incidents, accidents, false flag operations”. Nato has invited Russia to a fresh series of talks to discuss European security and arms controls as the alliance scrambles to avoid a possible Russian attack on Ukraine. “The main task now is to prevent a military attack on Ukraine,” Stoltenberg said after a meeting with the German chancellor, Olaf Scholz. “We are willing to listen to their concerns but we will not compromise on core principles. We must remain clear-eyed about the prospects of progress but … will make every effort to reach an agreement.” A senior European official confirmed that the coming month is seen as the most likely time for a Russian offensive, if Vladimir Putin takes the decision to attack. “We all have the same assessment because it’s thought that the ground will be too muddy after mid-February,” the official said. “For a highly capable army, winter is actually very helpful.” Blinken will meet Ukraine’s president, Volodymyr Zelenskiy, and other senior officials in Kyiv on Wednesday. In Berlin, the secretary of state will meet with members of the new German coalition government as well as representatives of the “trans-Atlantic quad”, which also includes the UK and France. Those talks will be focused on preparing for the Lavrov meeting and working on a concerted response to any Russian attack. The German chancellor, Olaf Scholz, has not said definitely if the Nord Stream 2 gas pipeline from Russia to Germany would be suspended if Russia does attack, and there are reports that the threat of cutting Russia off from the Swift international payments system may have been quietly shelved. A senior European diplomat said that no final decisions had been made on Swift. “The aim being to really hinder and restrict Russia’s access to the global economy, so all those things – access to capital, access to banking – they remain on the table,” the diplomat said. “They have varying degrees of difficulty and vulnerability, so we need to do a proper assessment of what the Russians might do in response to each and any of those measures, and then work out which one is likely to be the most effective taken in the round.” In Kyiv, Blinken is due to talk to US embassy staff about their contingency plans in the event of a Russian attack. “We are conducting normal contingency planning, as we always do, in terms of our embassy and US citizens in Ukraine,” a state department official said. “That is normal any time we see a security situation severely deteriorating, as we are seeing in Ukraine.” The US senator Chris Murphy, who has been holding talks with Ukrainian leaders on a congressional delegation visit to Kyiv, said: “I think Ukraine is ready. Ukraine is battle tested. “This is a country that knows how to fight, but my worry is that Putin is living in some hermit hole, having been convinced by a small set of bleary-eyed advisers that he’ll be greeted as a liberator when he heads for the Dnieper.” The talks in Geneva follow inconclusive meetings last week between the US and Russia, as well as a rare meeting of the Nato-Russia Council, where Russia tabled uncompromising demands about the future security architecture of Europe, including legally binding guarantees that neither Ukraine nor Moldova will be allowed into Nato. Moscow wants a pullback of Nato troops from close to the Russian border and an end to some intermediate nuclear weapons in Europe. The fresh invitation to talks from Nato may be a last-ditch attempt to show Putin that dialogue will give him substantive progress on arms controls that he can sell to a domestic audience, and that by comparison a military intervention represents an incalculable political risk for him. But Nato and Russia appear far apart on the agenda for the talks. Standing alongside Stoltenberg, Scholz said: “We all want stable and constructive relations with Russia. We have no interest in permanent tensions.” He added there were difficult considerations about how to sequence the issues in any talks with Russia. He also came under pressure to say whether he regarded the Nord Stream 2 gas pipeline from Russia to Germany as a purely commercial contract. He implied the project would stop if there was an invasion by saying he stood by an agreement Germany signed with the US last year. The Stoltenberg offer came as the German foreign minister, Annalena Baerbock, met her Russian counterpart, Sergey Lavrov, in Moscow. Baerbock said it was hard to see the buildup of Russian troops as anything but a threat to Ukraine and that her country was prepared to pay a high price to defend its values. Baerbock also called for an urgent return to dialogue on the future of Ukraine through the Normandy Format, the four-way dialogue between Germany, Russia, France and Ukraine. Lavrov said he would welcome US involvement in the Normandy Format, claiming it was impossible at present to persuade Ukraine to examine the necessary issues, including the legal status of the Donbass, the separatist region within Ukraine. Lavrov defended the right of Russia to move its troops within its borders and demanded the promised written answers from both Nato and the US to Russia’s call for a rewriting of European security architecture including legally binding guarantees that neither Ukraine or Moldova will be admitted to Nato.