The US observed ongoing fighting in Kherson and Mykolaiv on Sunday and Russian forces are still trying to encircle Kyiv, Khakhiv, Chernihiv, and Mariupol, according to the official.
But the advances have been met with strong Ukrainian resistance, slowing the Russian assault.
Read more: Day Twelve of Ukraine Defending Against Russian Invasion (Live Updates)
Meanwhile, the massive Russian convoy north of Kyiv that spans some 40 miles of road remains stalled, but there is no update on how far it is from Kyiv. Late last week, it was approximately 16 miles (25 kilometers) from Kyiv's city center.
The skies above Kyiv remain contested, and both Ukrainians and Russians retain a significant majority of their air combat power.
“We believe the Ukrainian people in most parts of the country still have means of communication, access to internet and the media,” the official added.
The official also said the US has not observed an amphibious assault near Odessa and they do not assess one is imminent.
The official could not confirm reports of Russians firing on protestors in Kyiv or violations of the ceasefire agreement to allow for humanitarian corridors. The official also could not corroborate reports the Russians are calling up reserves.
Read more: Ukraine’s Marine Corps Headquarters: At Least 30 Russian Helicopters Shot Down by the Ukrainian Warriors Nearby Kherson
