The Estonian Foreign Intelligence Service also warned that Russia would likely launch an armed conflict with NATO if it wins in the war in Ukraine.
Ukraine's President Volodymyr Zelensky made a surprise visit to the UK where he appealed for more weapons to use in the war against Russia.
President Joe Biden delivered his second State of the Union address on Tuesday.
First Lady Jill Biden invited twenty-six individuals to watch her husband's second State of the Union Address.
German Defense Minister Boris Pistorius said Western countries will continue to provide Ukraine with weapons despite Russian threats.
Wagner founder Yevgeny Prigozhin made the challenge in a video published by his press service.
The research estimates that for every soldier killed, three or four are wounded in combat.
There are currently two private military groups deployed to the war in Ukraine.
Chechen Leader Ramzan Kadyrov said he has the personal intention of "fighting Satanism" throughout Europe, beginning with Poland.
President Joe Biden on Tuesday will deliver his second State of the Union address to likely his largest audience of the year.
Ukraine is set to send rescuers to Turkey after a 7.8 magnitude earthquake struck Turkey and Syria on Monday.
A Russian web magazine last month interviewed former Wagner fighters who said the group follows an "attack or be shot" discipline.
Top Ukrainian official Oleksii Danilov claimed Brazil is one of the countries Russia is looking to act as an intermediary between Kyiv and Moscow.
Ukrainian Utah State basketball player Max Shulga noted that "emotions can run high" during the game, and people can say things they do not really mean.
Ukrainian civilians in the city of Tokmak are being asked to move out onto the streets in order to accommodate local collaborators.
Ukraine says Russia's military death toll in the war has reached over 131,200.