NATO chief Jens Stoltenberg said there were not yet signs of de-escalation over Ukraine.
Russia's claims it is withdrawing troops from the Ukrainian border is false, the US and NATO have said, with the number actually increasing by 7,000.
NATO chief Jens Stoltenberg told reporters ahead of a defence meeting in Brussels on Wednesday that the West had "not seen any withdrawal of Russian forces and, of course, that contradicts the message of real diplomatic effort [from Russia]."
"What we have seen is they have increased the number of troops and more troops are on their way."
He warned after the meeting that Russia's use of force is "the new normal in Europe" and that it was maintaining "a massive invasion force ready to attack with high-end capabilities from Crimea to Belarus".
US State Department spokesman Ned Price said the US had seen "more Russian forces, not fewer" with a senior official adding that an additional 7,000 troops had been detected, with some arriving as recently as Wednesday.
Moscow claimed on Tuesday that some of its troops had started to pull back from the border because they had "completed their mission".
US President Joe Biden said on the same day that Russia had gathered more than 150,000 troops on the Ukrainian border.
The Kremlin has repeatedly denied that they are planning an invasion despite amassing troops near Ukraine.
NATO defence ministers agreed on Wednesday to consider establishing new battlegroups in central, eastern and south-eastern Europe, Stoltenberg said.
"It is not too late for Russia to step back from the brink of conflict and choose the path of peace," he said.
There has been hope that a diplomatic solution to the crisis is still possible, with Russian foreign minister Sergei Lavrov saying talks should be expanded and President Vladimir Putin adding that Russia does not want a war.
Russia has requested that NATO does not incorporate other former Soviet countries and that it roll back its deployments in eastern Europe.
"NATO will not compromise on core principles, the right of each nation to choose its own path and our ability to protect and defend all allies," Stoltenberg said on Wednesday.
Russia repeated on Wednesday that they would return more troops and weapons to bases in what appeared to be an effort to quell fears that they are planning to invade Ukraine.
The Russian Defence Ministry released a video showing armoured vehicles moving across a bridge away from Crimea, the Black Sea peninsula that Russia annexed from Ukraine in 2014.
Russian fighter jets flew over Belarus on Wednesday and paratroopers held drills as part of war games.
Belarusian Foreign Minister Vladimir Makei said that all Russian troops will leave the country after the drills wrap up this weekend.
Biden and UK Prime Minister Boris Johnson agreed on Monday that there remained a "crucial window for diplomacy".
"As long as there is hope of a diplomatic resolution that prevents the use of force and prevents the incredible human suffering that would follow, we will pursue it," Biden said in a televised address on Tuesday.