In the unannounced visit, Annalena Baerbock said she wanted to get a picture of the situation on the ground.

“Above all, I want to listen to the residents, who are being so hard hit by the war in this bitterly cold winter, when temperatures are currently dropping in the night to -15C,” said the minister, whose visit was kept secret for security reasons and announced only as she made her way back to Berlin.

“In all parts of Ukraine, from Kharkiv to Kherson to Kyiv, people should know that they can rely on our solidarity and support,” she said.

The help includes deliveries of power transformers, blankets but also weapons, she said, “that Ukraine needs in order to free its citizens who are still suffering under the terror of Russian occupation”.

Germany will also provide assistance as Ukraine embarks on its journey to join the European Union, said Baerbock.

“As the government, we want to make very concrete offers to Ukraine in order to strengthen the rule of law, independent institutions and the fight against corruption, as well as in aligning with EU standards,” she said.

Several Western leaders including Chancellor Olaf Scholz and French President Emmanuel Macron have visited Ukraine since Russia’s invasion on February 24th.

But none have travelled so far east where swathes of territory are in the hands of Russian troops.

Kharkiv had been heavily shelled by Russian troops early in the war, but Ukrainian forces were able to defend the city and repel the attacks.

The front has since receded, and is currently about 130 kilometres (80 miles) from Kharkiv.

Baerbock’s surprise visit came just days after Scholz agreed to provide to Ukraine Marder infantry fighting vehicles long sought by Kyiv.

The latest trip is her third to the conflict-torn country since Russia’s February 24th invasion.

In May, she became the first senior Germany government figure to travel to Ukraine since the conflict.

During that trip, Baerbock announced the reopening of Germany’s embassy in the country. She also visited Bucha, a town outside Kyiv where Russian troops have been accused of war crimes.