Russian advances are halted by strong Ukrainian resistance, resulting in losses.

• According to the U.K. Ministry of Defence, Russian forces are experiencing losses and some Russian soldiers have been captured by Ukrainian forces.
• On Saturday in Washington, a U.S. Defense official stated that the Pentagon has no evidence that the Russian military has seized any Ukrainian cities.
• Russian units were repulsed by Ukrainian troops, aided by volunteers, in the early morning hours of Saturday local time.

According to U.S. and U.K. officials, the stubborn Ukrainian resistance and logistic difficulties are hindering Russian attacks more than Moscow planners anticipated, and there is no evidence that the invading forces have captured any significant Ukrainian cities.

The U.K.'s Ministry of Defence stated on its verified Twitter account that Russian forces are not advancing as planned due to logistical difficulties and robust Ukrainian opposition.

Ukrainian forces, aided by volunteers, successfully defended Kyiv against a Russian attack in the early morning hours on Saturday local time. Reports indicate that fighting is taking place in and around several Ukrainian cities.

On Friday, a U.S. Department of Defense official shared information with CNBC, which was later corroborated by a British report.

The U.K. ministry stated that Russian forces are incurring losses and some Russian soldiers have been captured by Ukrainian forces.

‘Momentum continues to be slowed’

On Saturday in Washington, a U.S. Defense official, speaking anonymously, stated that the Pentagon has not received any evidence indicating that the Russian military has seized any Ukrainian cities.

The military situation in Ukraine is constantly changing, and it is challenging to confirm the accuracy of individual accounts.

The official stated that about 60% of the Russian troops that were positioned near the borders prior to the invasion are now present in Ukraine, which is an increase from the previous estimate of 33% given on Friday.

According to reports, Russia is estimated to have gathered approximately 190,000 troops near Ukraine. However, a U.S. Defense official refused to provide further details on Russia's force posture, stating that the Russians' momentum has been slowed mainly due to strong Ukrainian resistance.

According to a January report from the U.S. Congressional Research Service, Ukraine's army has approximately 145,000 to 150,000 troops.

The official stated that the toughest combat in Ukraine is currently taking place in the northeastern city of Kharkiv, and that the Russians are encountering strong opposition as they attempt to advance northward toward Kyiv.

The official warned that the estimate is a "static" and will not change "hour by hour."

Weapons going into Ukraine

On Saturday, a U.S. Defense Department official confirmed to CNBC that the next batch of U.S. aid to Ukraine, as announced by Secretary of State Antony Blinken earlier in the day, would include Javelin missiles.

The Javelin, produced by two defense corporations, is a portable, shoulder-mounted missile intended to destroy tanks.

Germany's arms-export policy has undergone a significant shift, as Chancellor Olaf Scholz announced that his country will provide Ukraine with 1,000 anti-tank weapons and 500 stinger missiles.

Stinger missiles, like Javelins, can be carried by one person and are designed to shoot down helicopters and fixed-wing aircraft.