As the war in Ukraine enters its fourth week, British intelligence says Russian forces are mostly bogged down on all fronts amid what it described as a "staunch and well-coordinated" Ukrainian resistance.
"Russian forces have made minimal progress on land, sea, or air in recent days and they continue to suffer heavy losses," British intelligence said in a March 17 update.
Heavily outnumbered Ukrainian forces have prevented Russian troops from capturing any of Ukraine's biggest cities so far despite the largest assault on a European state since World War II.
"The vast majority of Ukrainian territory, including all major cities, remains in Ukrainian hands," British intelligence said.
More than 3 million Ukrainians have fled the country, and thousands of civilians and military service members have been killed amid the fighting.
Mariupol has been the scene of the worst humanitarian catastrophe, with hundreds of thousands of civilians trapped in their basements with no food, water, or power. Russian forces agreed on March 14 to allow for a humanitarian corridor out of the besieged port city, with Sky News reporting that some 20,000 people have now managed to flee.
Some of the suburbs of Kyiv have been reduced to rubble by heavy fighting, although the capital itself has held firm.
The prime ministers of Poland, the Czech Republic, and Slovenia traveled to Kyiv on March 15, braving a risky train trip through a war zone to demonstrate their support for Ukraine.
Polish Prime Minister Mateusz Morawiecki described the struggle as one between freedom and tyranny.
Russia has denied targeting civilian infrastructure or civilians.
Skrzypczak said both sides have ceased major maneuvers and have mostly dug in defensively, with troop-on-troop combat mostly confined to small-scale, localized offensives and counter-attacks.
"There's now a race on for which side can gain an advantage" by mobilizing their respective reserves and "launching counter-offensives or large-scale assaults against opposing forces," he said.
The retired general added that he believes Russian troops have been heavily battered by three weeks of combat against Ukrainian forces.
"Russian forces are tired and spent from this fight. It makes no difference whether they're being resupplied with ammunition or not, 20 days of combat is a huge effort for soldiers to undertake and absorbs a lot of energy," Skrzypczak said.
British intelligence assessed on March 16 that Russia's lack of significant progress in its advance was likely leading to "the use of older, less precise weapons, which are less militarily effective and more likely to result in civilian casualties."
"Latest U.N. reporting indicates that 1,900 civilian casualties, including 726 deaths, have already occurred in the conflict to date. The true casualty figure is likely to be significantly greater and will continue to rise as long as the conflict continues," British intelligence said.
Both sides have said there's been progress in peace talks.
Ukrainian officials have said they think Russia is running out of troops to keep fighting and could soon come to terms with its failure to topple the Ukrainian government. Moscow has said an agreement is close on an arrangement that would keep Ukraine neutral, a key demand by Russia, which fears Kyiv's ambitions to join NATO.
Moscow said peace talks resumed on March 17 by video link for a fourth straight day, focusing on military, political, and humanitarian issues.
"We support Ukraine because we know what they can achieve on the negotiating table is of course very closely linked to the situation on the battlefield," Stoltenberg said.
"So I strongly also believe that one reason why the Ukrainians also are saying that they have seen some steps in the right direction is because they have been able to fight back. They have been able to fight back against the invading Russian forces."