Ukrainian President Volodymyr Zelenskiy asked Olaf Scholz to show full-throated support for Kyiv, charging the German Chancellor with being too concerned about the repercussions that would have for Berlin's ties with Moscow.
Zelenskiy's comments, made in an interview with German public broadcaster ZDF, come amid speculation that Scholz could make his first trip to Kyiv since the start of the war on Thursday.
"We need from Chancellor Scholz the certainty that Germany supports Ukraine," he said. "He and his government must decide: there can't be a trade-off between Ukraine and relations with Russia."
Online magazine Focus, citing Italian newspaper La Stampa, reported that the three European leaders would travel to the Ukrainian capital on Thursday, adding a specific date to a Bild am Sonntag report on Sunday that they planned to go before a Group of Seven summit at the end of June.
Germany has yet to confirm any of these reports.
Kyiv and its western allies have criticised all three countries for alleged foot-dragging in their support for Ukraine in its battle against Russian invaders in its east, accusing them of being slow to deliver weapons or of putting their own prosperity ahead of Ukraine's freedom and security.
Scholz, like the other two leaders, rejects these charges. Until now, he has rebuffed calls for him to visit Kyiv, saying he would only go there once he had something concrete to announce.
At home, frustration has also grown among Scholz's junior coalition partners over what they say are shortcomings in his leadership on Ukraine, an internal rift that risks undermining Western unity against Russia.
Earlier on Monday, he told reporters that Germany was sending Ukraine some of the world's most advanced mobile artillery systems, adding that this had taken time, since Germany had first needed to train Ukrainian crews to use them.