"Whatever (the Ukrainians) do, it will be carefully planned, kept secret and will likely be extremely well executed," Ingram added.
Some residents in Kherson, meanwhile, are concerned about the risk of Russian shelling of the city once its forces regroup further east.
"This Kherson fire support base becomes the anchor to support further manoeuvre by the left flank as it fights its way ... towards Mariupol, Berdyansk, and Melitopol."
White House National Security Advisor Jake Sullivan told reporters on Friday that the United States would continue to support Ukraine militarily "to put Ukraine in the best possible position on the battlefield" and would not seek to tell it what to do.
They still control large parts of Ukraine ... What we should do is strengthen Ukraine's hand," Stoltenberg added.