Kiev, 20 February 2023 (dpa/MIA) - US President Joe Biden made a surprise visit to Kiev on Monday, announcing new aid and military equipment for Ukraine, as well as further sanctions against Moscow, in a highly symbolic show of support as the first anniversary of Russia's full invasion looms.

"One year later, Kyiv stands. And Ukraine stands. Democracy stands," Biden said, using the common Ukrainian pronunciation of the capital city, as quoted by journalists travelling with the president.

Ukrainian President Volodymyr Zelensky praised Biden for his "historical" and "brave" visit to Kiev at "the most difficult time."

It is the first time a US president has visited a war zone without US military being on the ground, as the White House stressed. The decision to undertake the dangerous journey had been Biden's own, to present a united front to Russian President Vladimir Putin.

In joint remarks with Zelensky, Biden announced $500 million in additional assistance to Ukraine, as well as more military equipment including artillery ammunition, Javelins and Howitzers - all items the US has already been supplying.

Zelensky said they had spoken about "long range weapons" and arms that had not yet been supplied to Ukraine, without detailing any new commitments, according to the journalists travelling with Biden.

Their talks brought Ukraine "closer to the victory," Zelensky told the media. "Today our negotiations were very fruitful ... They were very important and crucial."

"Russia's aim was to wipe Ukraine off the map," Biden said. "Putin's war of conquest is failing."

The US president had arrived in Ukraine early on Monday under the strictest security precautions, for his first visit to the country since the outbreak of war, and his first time there as president. An air raid siren sounded during his visit.

The trip, ahead of a scheduled visit to Poland later on Monday, was long kept secret for security reasons. The White House had repeatedly denied rumours that Biden would take the opportunity to visit neighbouring Ukraine.

Russia had been informed shortly ahead of the trip, however, according to US National Security Advisor Jake Sullivan.

"Because of the sensitive nature of those communications I won't get into how they responded or what the precise nature of our message was, but I can confirm that we provided that notification," Sullivan said on a phone call with journalists.

Biden and Zelensky appeared in public at St. Michael's Golden-Domed Monastery in central Kiev and laid a wreath for the Ukrainians who had fallen during the war.

The visit, so close to the anniversary of the full-scale invasion on February 24, is seen as highly symbolic.

In Berlin, the German government said it was a "good signal," without going into further detail.

Polish leaders welcomed it as a firm indication of US commitment to supporting Ukraine in its fight against invading Russian troops.

"We welcome the announcement of military aid with satisfaction because it brings us much closer to peace," Marcin Przydacz, foreign policy advisor to Polish President Andrzej Duda, wrote on Twitter.

Washington has so far provided or promised military aid to Ukraine to the tune of almost $30 billion since the start of the war, according to the Pentagon. This includes various heavy weapons systems.

Biden and his administration have assured Ukraine that they will stand by the country for as long as it is necessary - a message he delivered to Kiev in person on Monday.

"Putin thought Ukraine was weak and the West was divided," Biden said. "He thought he could outlast us. I don’t think he's thinking that right now."

In Kiev, he stressed that Western allies had already provided Ukraine with 700 tanks, thousands of infantry fighting vehicles and artillery systems and almost two million artillery shells, with more to come.

On Tuesday, Biden plans to hold a speech in Warsaw - on the same day as Putin is due to give an address in Moscow.

In Poland, Biden also plans to meet Duda, before meeting representatives of other eastern NATO allies on Wednesday.

Meanwhile, Japan pledged a further $5.5 million in support for Ukraine. Prime Minister Fumio Kishida is planning an online meeting of G7 partners for Friday, the anniversary of Russia's full-scale invasion. Zelensky would also be invited, he said according to Japanese media.