The United States on Thursday challenged Russia to declare that it would not invade Ukraine and support it by pulling back troops.

At a United Nations Security Council meeting in New York to discuss the showdown over Ukraine, US Secretary of State Antony Blinken said that Russia was laying the groundwork to justify starting a war with its neighbour. Citing US intelligence, he said Moscow was preparing to invade Ukraine in the “coming days”.

Blinken, who changed his travel plans so that he could speak at the UN meeting, challenged the Kremlin to “announce today with no qualification, equivocation or deflection that Russia will not invade Ukraine”. He added that the Russian government should state this clearly if it seeks peace.

“And then demonstrate it by sending your troops, your tanks, your planes, back to their barracks and hangars and sending your diplomats to the negotiating table,” Blinken said. “In the coming days, the world will remember that commitment – or the refusal to make it.”

Since early this year, Russia has amassed over 1 lakh troops at the Ukrainian border. Reports also said that 30,000 more are engaged in exercises in Belarus, close to its border with Ukraine. The two countries have been engaged in a conflict since 2014 when Russia annexed Ukraine’s Crimean Peninsula and backed separatist rebellions in the country’s eastern regions of Donetsk and Luhansk.

Along with the US, allies of the North Atlantic Treaty Organization have rejected Russian claims that it was pulling back troops from exercises that have raised fears of an imminent invasion. The Kremlin has consistently maintained that it has no plans to invade but has for long considered NATO’s eastward expansion an existential threat.

At Thursday’s meeting, Blinken told the diplomats about several steps that the US expected Russia to take in the coming days in an attempt to justify military action in Ukraine.

He claimed that a sudden, seemingly violent event staged by Russia would start the attack. “Russia may describe this event as ethnic cleansing or a genocide, making a mockery of a concept that we in this chamber do not take lightly,” Blinken said.

After this, he said Moscow could “manufacture” a pretext to invade, would then bomb Ukraine, kickstart cyberattacks to shut down its institutions and then send tanks and soldiers in to occupy the country.

“We believe these targets include Russia’s capital – Ukraine’s capital, Kyiv, a city of 2.8 million people,” the senior US official said.

Blinken acknowledged that some people have raised questions about the US intelligence claims. “But let me be clear: I am here today, not to start a war, but to prevent one,” he added.