In some Ukrainian cities, the Russian forces will hold fire and establish corridors. Oil prices have risen as a result of the conflict: Updates in real time

 According to US Secretary of State Antony Blinken, NATO countries aiding Ukraine against the Russian invasion have the "green light" to send fighter jets as part of their military assistance.

The call for increased air help comes as Russia continues to shell a number of Ukrainian cities in the south, stifling evacuation efforts and resulting to an increase in civilian deaths and displacement. Ukraine's military has shot down Russian bombers with fighter jets, drones, and anti-aircraft weapons mostly supplied by NATO.

During an interview with CBS News' "Face the Nation," Blinken said, "We're discussing with our Polish friends right now about what we might be able to do to backfill their needs if, in fact, they chose to deliver these fighter jets to the Ukrainians."

However, Ukrainian President Volodymyr Zelenskyy's request for a no-fly zone above his nation remains unpopular. "The world is strong enough to close our skies," Zelenskyy declared in a video message on Sunday. In addition, he called for tougher sanctions on Russia.

NATO members have ruled out enforcing a no-fly zone over Ukraine, which would prevent all unauthorized aircraft from flying over the country. Any third-party proclamation of a no-fly zone over Ukraine, according to Russian President Vladimir Putin, would be considered "participation" in the military conflict.

Blinken also claimed that the US and its allies are discussing banning Russian oil imports, a move that would necessitate successful measures to secure a "enough supply of oil on world markets." About 30% of Europe's oil and 40% of its natural gas are supplied by Russia.

According to a senior Defense Department official, the Russian military maintained its efforts over the weekend to isolate Ukraine's key cities, including Kyiv. Forces attacking near Kyiv, Kharkiv, and Chernihiv in northern and eastern Ukraine, on the other hand, are encountering stiff resistance, according to the official.

According to the person, who spoke on the condition of anonymity to discuss intelligence results, the airspace over Ukraine remains contested.