BERLIN, Germany — German Chancellor Olaf Scholz said on Tuesday rebuilding Ukraine was a "generational task" that must start immediately, even as Russia's invasion rages on.

"What is at stake here is nothing less than creating a new Marshall Plan for the 21st century — a generational task that must begin now," Scholz said as he opened an international reconstruction conference for Ukraine in Berlin.

Ukrainian President Volodymyr Zelensky on Tuesday asked the international community to cover an expected budget deficit of $38 billion next year for his war-torn country.

"At this very conference we need to make a decision on assistance to cover next year's budget deficit for Ukraine," Zelensky said via video-link at a reconstruction conference in Berlin.

Meanwhile, German President Frank-Walter Steinmeier arrived in Kyiv on Tuesday, his spokesperson told AFP, confirming his surprise visit to Ukraine.

The trip is his first to the country since Russia invaded Ukraine in February, and came six months after Steinmeier, then under heavy fire for his years-long detente policy with Moscow, was snubbed by Kyiv.

The president also had to abort a trip at the last minute last week over security reasons, sparking criticisms from Germany's opposition.

"I am looking forward to my meeting with (Ukrainian) President Volodymyr Zelensky in Kyiv," he said, according to a confirmation sent by his spokeswoman.

Before meeting Zelensky, Steinmeier will visit a town in the north of the country, near the Belarusian border, which Ukraine says has been liberated from Russian troops but left with its infrastructure destroyed.

Steinmeier will provide aid to the municipality for its energy infrastructure, he said.