Kyiv, Ukraine - Treasury Secretary Janet Yellen met Ukrainian President Volodymyr Zelensky on Monday during an unannounced visit to Kyiv Russia's attack on Ukraine intensified, according to government statements.

The US official assured Ukraine's leader of continued US assistance by announcing the release of $1.2 billion in aid to Ukraine, according to the US Treasury Department.

This is the first part of a total of around $10 billion of planned US aid for Ukraine, to be released over the coming months.

Yellen had already announced the additional aid package last week. The United States has already sent over $13 billion to Ukraine in the last year.

Joke of the Day Joke of the Night for April 22, 2024: The best jokes to laugh the day away

In her conversation with Zelensky, Yellen delivered a message from President Joe Biden that the US would stand by Ukraine as long as it was needed, read the statement.

According to Kyiv, Zelensky thanked the US for its enduring support since the beginning of Russia's war.

Last week, Biden also met Zelensky during a surprise visit to Kyiv. Biden promised to support Ukraine in its fight against Russia for as long as necessary and announced additional military aid of up to $460 million. This brings the total US military, financial and humanitarian aid to Ukraine up to $50 billion so far.

According to official reports, the Ukrainian Commander-in-Chief Valerii Zaluzhnyi also had a phone call with Chief of Staff Mark Milley on Monday. They discussed the current situation as well as international arms deliveries for Ukraine.

Zaluzhnyi stressed that his country urgently needed US F-16 fighter jets. Though the US has provided Ukraine with huge amounts of aid, they have so far refused to provide them with aircraft.

On the same day, war-torn Ukraine reported intensified fighting in eastern Ukraine, particularly near Bakhmut, a town of strategic importance in the Donetsk region which has been contested for weeks.

Ukraine said its soldiers were under pressure in Bakhmut, which has been bitterly fought over for the last six months. Kyiv added that the almost completely destroyed town is not being abandoned however, in an effort to demoralize Russian troops.

Viral Video of the Day Viral Video of the Day for April 23, 2024: Dad's beautiful singing melts his daughter's heart on TikTok!

Kyiv's General Staff report also reported Russian attacks in Kupyansk, Lyman, Avdiivka and Vuhledar.

The attacks at Avdiivka, which is close to Donetsk, and at Vuhledar were repelled, it said.

According to Ukrainian intelligence, the Russian army has brought more soldiers into Ukraine, with reports of around 200 conscripts arriving in the country from the neighboring Russian Rostov region. The military figures could not be independently verified.

The Russian Defense Ministry also reported an intensification of the Donetsk offensive with renewed artillery and airstrikes.

In the area around Bakhmut, an ammunition depot of the Ukrainian armed forces was hit, a spokesman for the Russian Defense Ministry, Igor Konashenkov, said on Monday.

Russian artillery destroyed tanks, armored equipment and vehicles belonging to the Ukrainian military, Moscow said.

As heavy fighting continues, there were reports of some reshuffles amongst top Ukrainian officials.

Eduard Moskalyov is no longer commander of the joint forces, according to a decree issued late on Sunday night. Moskalyov has held the post since March 2022, shortly after the Kremlin launched its full invasion of Ukraine a year ago. A reason for the sacking was not given.

Ukrainian railway chief Oleksandr Kamyshin also announced his resignation on Monday.

"It is the 369th day of the war. The railway continues to work according to plan," the 39-year-old wrote on the Telegram news channel on Monday. He said he would now take over the office on EU integration of Ukrainian Railways.

Kamashin did not say anything about the reasons for his departure; however, it had been agreed with the vice-government head responsible for transport, Oleksandr Kubrakov.

The railway, which is running despite Russia's war, became a symbol for the continued functioning of the Ukrainian state.