Russians have advanced in the east of Ukraine because the US Congress has delayed providing aid to Kyiv, and Russia may have new tactical successes on the front in the coming weeks. This was stated at a briefing by US National Security Advisor Jake Sullivan.

The delay in American aid has forced Ukraine to save shells and as a result, it has lost some of its territory, including Avdiivka.

"And while today's announcement (of aid) is very good news for Ukraine, they are still under serious pressure on the battlefield, and it is possible that Russia could gain additional tactical advantages in the coming weeks," Sullivan said.

He noted that "it will take some time to get out of the hole". 

At the same time, he said, Ukrainian troops, while awaiting help from the USA, were able to inflict "significant losses on Russia, destroying 700 Russian armored vehicles and approximately 250 tanks."