Russia’s Defense Ministry announced new military operations in several regions near the Ukrainian border on Thursday , even as Chancellor Angela Merkel of Germany warned the Kremlin to abandon the politics of the 19th and 20th centuries or face diplomatic and economic retaliation from a united Europe.

In Moscow, the military acknowledged significant operations involving armored and airborne troops in the Belgorod, Kursk and Rostov regions abutting eastern Ukraine, where many ethnic Russians have protested against the new interim government in Ukraine’s capital, Kiev, and appealed to Moscow for protection.

A day after a deputy minister denied any military buildup on the border, the Defense Ministry released a series of statements beginning early Thursday that appeared to contradict that. They outlined what was described as intensive training of units involving artillery batteries, assault helicopters and at least 10,000 soldiers.

The operations confirmed, at least in part, assertions by Ukrainian leaders on Wednesday that Russia was massing forces, as well as amateur photographs that appeared to show columns of armored vehicles and trucks in a border village called Lopan, only 30 miles from the Ukrainian city Kharkiv. One statement announced that another 1,500 paratroopers from Ivanovo, east of Moscow, had parachuted onto a military base in Rostov, not far from the Ukrainian cities Donetsk and Lugansk. . . .

Appearing before Parliament on Thursday, Ms. Merkel criticized Russia’s actions in some of her toughest language to date, declaring that “the territorial integrity of Ukraine cannot be called into question.”

“Ladies and gentlemen, if Russia continues on its course of the past weeks, it will not only be a catastrophe for Ukraine,” she said. “We, also as neighbors of Russia, would not only see it as a threat. And it would not only change the European Union’s relationship with Russia. No, this would also cause massive damage to Russia, economically and politically. . . .”

Mr. Putin, who has remained in Sochi to attend the Paralympics there, has so far showed no sign of bending to international criticism. In a meeting on Wednesday with the directors of national Paralympic teams, he implicitly reiterated the Kremlin’s argument that the ouster of Mr. Yanukovych was an armed coup instigated by outside forces. “I would like to assure you that Russia was not the initiator of the circumstances we are now facing,” Mr. Putin said. . . .

On Wednesday, the head of Ukraine’s National Security and Defense Council, Andriy Parubiy, claimed that Russian forces near the border totaled more than 80,000 solders, 270 tanks, 370 artillery systems and 140 combat aircraft. “Ukraine today is facing the threat of a full-scale invasion from various directions,” he said.

Image: Russian light infantry fighting vehicles 12 miles from Ukrainian border, March 12, 2014 (photo: Reuters)