Russian troops are no longer in full control of the southern Ukrainian city of Kherson after a counter-attack by Ukrainian forces, a senior US Defense Department official said Friday, according to NBC News . Russian forces captured Kherson in the first week of its invasion, the first major city to be captured after invading the country last month. “We can’t corroborate exactly who is in control of Kherson, but the point is it doesn’t appear to be as solidly in Russian control as it was before. The Ukrainians are trying to take Kherson back,” the Defense official told reporters on Friday. “We would argue that Kherson is actually contested territory again,” the official added, noting there was now "heavy fighting" under way in Kherson. If Russia lost Kherson in the south, it would represent a major battlefield setback and complicate any attempt by it to capture the Black Sea port of Odessa, the Defense official said. If the Ukrainians took back Kherson, “that would be a significant development, no question about that,” the official added. Earlier on Friday, the Russian Ministry of Defense announced that the first phase of the military operation in Ukraine has been largely completed and that Russia will now focus on the "complete liberation" of the Donbas region in eastern Ukraine. The ministry reported that 1,351 Russian troops have died and 3,825 have been injured since the beginning of the operation. Related articles: Trump Admin. has set date for full ceasefire in Ukraine One dead in Ukrainian attack on Moscow Is Russia planning to attack another European country? Ukrainian Jews remain hopeful amid tensions with Washington (Israel National News' North American desk is keeping you updated until the start of Shabbat in New York. The time posted automatically on all Israel National News articles, however, is Israeli time.)