Russia has said it is willing to continue talks with the US over European security, but is not optimistic about their prospects after Washington and Nato allies again rejected a key part of Russia’s proposed new order for post-cold war security. Tensions have soared in recent weeks as Russia massed more than 100,000 soldiers and heavy weapons at its border with Ukraine, raising fears of an invasion. “We continue to see, including in the last 24 hours, more accumulation of credible combat forces arrayed by the Russians in, again, the western part of their country, and in Belarus,” said John Kirby, the defence department spokesman, on Thursday. Meanwhile, the US is accelerating arms supplies to Ukraine. “We are just at the beginning of a whole new package of assistance material,” Kirby said. “There’s been three shipments. More that will be coming.” Asked about the Ukrainian request for air defence missile systems, Kirby noted that a US air and missile defence assessment team had been in Ukraine recently to discuss the country’s needs. Kirby added: “I think you can understand why we would want to be careful about advertising publicly the kinds of capabilities that we’ve given to Ukraine, given the size and the scale and the capabilities that are arrayed against them on the other side of their border.” Earlier on Thursday, Vladimir Putin’s chief spokesman, Dmitry Peskov, said “there isn’t much reason to be optimistic” after the US and Nato rejected Moscow’s demands for a veto on Ukraine’s potential membership of Nato in a coordinated response the day before. Moscow needed time to analyse the US document and would not “rush into assessments”, Peskov added. Russia’s foreign minister, Sergei Lavrov, said Moscow’s main concern – the potential for Ukraine to join Nato – had not been addressed, but there was hope “for the start of a serious conversation on secondary issues”. “There is no positive response in this document on the main issue,” he said. One of Lavrov’s spokespeople appeared to rule out war with Ukraine, in comments that led to a jump in the value of the Russian rouble, as investors gained confidence that conflict could be avoided. “We have already repeatedly stated that our country does not intend to attack anyone. We consider even the thought of a war between our people to be unacceptable,” said Alexei Zaitsev, a spokesman for the foreign ministry. The focus turns again to Putin, who is yet to voice his response and is being briefed on the document. “The most important thing we heard from Moscow today is that the documents are with President Putin, that he is studying them,” the US undersecretary of state for political affairs, Victoria Nuland, said. “From where we’re standing, the ball is in their court, but we are ready for talks … whenever they are ready.” Ukraine’s president, Volodymyr Zelenskiy, gave an upbeat assessment on the latest diplomatic moves, noting that his diplomats would meet counterparts from Russia, Germany and France in two weeks’ time in Berlin. Diplomats from the four countries met in Paris on Wednesday and agreed to continue talking. Ukraine has been seeking to downplay reports of an imminent attack by Russia. One of Zelenskiy’s aides told Reuters the borderline “hysteria” about a Russian attack was hindering Kyiv’s attempts to borrow on international capital markets. Struggling to access private funds, Ukraine intends to seek $5bn (£3.7bn) in loans from governments and international institutions. On a visit to Copenhagen, seeking to marshal support from Nato member Denmark, Ukraine’s foreign minister, Dmytro Kuleba, gave his approval of the US response to Russia. Ukraine, he said, had seen it before it was hand-delivered to Russia’s embassy in Washington. Kuleba emphasised his country’s need for stronger defences and a unified position from the west on economic sanctions. “This crisis is a moment of truth, and this is why we speak about weapons,” he said. “This is why we speak about economic sanctions. This is why we speak about the consolidated position of all of us, so that President Putin sees that there are no weak links in our defensive chain.” Pressure on Russia grew after Germany’s foreign minister, Annalena Baerbock, gave a strong indication that the Nord Steam 2 gas pipeline would be part of the sanctions package if Moscow ordered an invasion. “We are working on a strong package of sanctions” with western allies, and it covers several aspects “including Nord Stream 2”, Baerbock told the Bundestag. In Washington, Nuland restated the US position on Nord Stream 2 cancellation. “We continue to have very strong and clear conversations with our German allies,” she told reporters. “And I want to be clear with you today: if Russia invades Ukraine, one way or another Nord Stream 2 will not move forward.” Baerbock reaffirmed that Germany would not lift its export ban on weapons, despite pressure from allies. Germany faced criticism from the mayor of Kyiv, Vitali Klitschko, who described Berlin’s offer to send 5,000 military helmets as a joke. Estonia is waiting for permission from the German government to export howitzer guns to Ukraine that were originally made in the Soviet Union, stationed in East Germany, then after German reunification exported to Finland, which passed them on to Estonia. “On the political side, the consultations on sanctions, as well as the military side, giving the Ukrainians additional armaments is all geared towards raising the price of potential aggression,” said the Estonian ambassador to the US, Kristjan Prikk. Meanwhile, Russia has suspended international monitoring of its military exercises which is required under a 1990 agreement called the Vienna Document. The suspension is to last until 28 February so will cover drills in Belarus, which have caused alarm because they include well-equipped combat units from the far east of Russia. “The reason cited by Russia was another wave of the Covid pandemics,” said Łukasz Jasina, a spokesman for the foreign ministry of Poland, which is currently chairing the Organisation for Security and Cooperation in Europe. Jasina noted that many states had temporarily suspended verification during the pandemic. However, another European official said Russia routinely found ways around the verification obligations. “Considering the currently tense security situation, it is an especially negative signal that speaks volumes,” the official said. “It also raises the question of whether arms control should even be a point of discussion between the west and Russia, whose real actions are based on neither transparency nor reciprocity. “Were there any real concerns about Covid, there wouldn’t be a gathering of thousands of troops from various locations.”