Washington, 4 March 2023 (dpa/MIA) - US President Joe Biden and German Chancellor Olaf Scholz have reiterated their commitment to support Ukraine as two of Kiev's closest allies met for private talks at the White House on Friday to discuss the war.

This was the chancellor's second visit to the White House in the nearly 15 months since he took office. Scholz was first in Washington in early February last year and Ukraine played a central role then too.

At that time, tens of thousands of Russian soldiers had already amassed at the Ukrainian border. Two weeks later, on February 24, 2022, Russia invaded Ukraine.

Ukraine mounted a skilled and stubborn resistance against its much larger neighbour. But as the war grinds into its second year the US and Europe are wrestling with big issues surrounding the continuing supply of arms and ammunition, plus what security guarantees can be given to Ukraine - which hopes to join the European Union and NATO - in the long term.

There were also questions about how Biden and Scholz will respond to demands in some quarters that the West press for peace talks to end the bloodshed, and how to sanction China if it supplies arms to Russia, but much of what was discussed during Friday's one-hour meeting remained behind closed doors.

In a short statement released following the talks, the White House merely said that Biden and Scholz spoke about "ongoing efforts to provide security, humanitarian, economic, and political assistance to Ukraine and the importance of maintaining global solidarity with the people of Ukraine" as well as "other global issues."

Scholz has said several times he believes his government needs to be in lockstep with the Biden administration when it comes to sending military aid to Ukraine.

After resisting calls from Kiev and NATO allies for months, Berlin agreed earlier this year to send its Leopard battle tanks to Ukraine.

"I want to thank you all for your strong and steady leadership. I mean that sincerely. It's made a world of difference," Biden told Scholz in the Oval Office before the doors closed and their scheduled meeting began.

"You stepped up to provide critical military support and you know, I would argue that beyond your military support, the moral support you gave Ukrainians has been profound," Biden said.

Biden called Scholz's dramatic increase in defence spending and decision to move away from Russian fossil fuels historic decisions.

Scholz's trip to Washington has been described as a quiet working visit. He came without travelling journalists or a business delegation. The leaders also didn't hold a press conference after their meeting.

Joint support for Ukraine over the past year has been critical, Scholz said during a brief press encounter before the talks.

"It is really important that we acted together," he said. "At this time I think it is very important that we give the message that we will continue to do so as long as it takes."

Scholz also stressed how good he thinks the state of relations with the United States is: "I really appreciate the very good cooperation between the two of us, our governments," he said in English as he sat beside Biden.

Recently, there had been conflicting accounts from the White House and the chancellor's office about how the commitment of battle tanks to Ukraine had come about.

Biden's national security adviser Jake Sullivan said last weekend that Germany had made the supply of US Bradley fighting vehicles a condition for the pledge of German Leopard tanks. The German government denied this.

The opposition in Berlin suspects these irritations could be the reason for the trip.

Friedrich Merz, the leader of the conservative Christian Democrats (CDU), told Redaktionsnetzwerk Deutschland that there was "possibly a problem to clear up" with the battle tanks.

There is "a whole series of contradictions. Maybe they want to talk about these contradictions," he said.