A defiant Volodymyr Zelensky has insisted Bakhmut "is not occupied" by Russia after a Moscow-backed mercenary group had claimed control.

Ukraine's president was speaking during a scene-stealing visit to Hiroshima, Japan, for the G7 summit.

Wagner founder Yevgeny Prigozhin had earlier claimed victory in Bakhmut.

But Ukrainian military sources told the BBC they still had control of a handful of buildings on the outskirts of the city.

At a press conference on the final day of the summit, Mr Zelensky refused to provide precise details. But he said the city, where the war's longest and bloodiest battle has raged since August, was "not occupied" by Russia "as of today".

"There are no two or three interpretations of those words," he added, after earlier confusion about his remarks on the status of the city.

It was in a video posted on Saturday that Wagner's Mr Prigozhin claimed his fighters - who have led the Russian assault on Bakhmut - were in full control of the city.

Mr Zelensky compared Bakhmut to Hiroshima, which was hit by an atomic bomb in World War Two, promising a similar "reconstruction" of his country.

Earlier on Sunday, he visited the Hiroshima Peace Memorial Park with Japanese Prime Minister Fumio Kishida - whose relatives died when the United States dropped the bomb on the city in 1945.

Mr Zelensky laid a wreath for those who were killed in the attack.

After a meeting with Mr Kishida, he strode into an auditorium at the peace park to speak to reporters.

As he entered, one journalist shouted from the back of the room: "Slava Ukraini" (glory to Ukraine). Mr Zelensky nodded to acknowledge her.

He drew several parallels between Hiroshima and Ukraine, saying that pictures of the Japanese city in ruins after bombing reminded him of present-day Bakhmut. He vowed there would be a similar "reconstruction and recovery" of Ukraine.

"Now Hiroshima has rebuilt their city, and we dream of rebuilding our cities," he said.

There had earlier been some confusion about the status of Bakhmut, after Mr Zelensky said "today Bakhmut is only in our hearts".

His office later clarified that he had not said that the city had fallen.

But Russian fighters at least control most of Bakhmut. Wagner mercenaries have concentrated their efforts there for months, and their relentless, costly tactic of sending in waves of men seems to have gradually eroded Kyiv's resistance.

Ukrainian forces have resisted calls for a tactical withdrawal to this point, but say that if they did pull out it would be a "Pyrrhic victory" for the Russians.

Mr Zelensky also alluded to his troops continuing to carry out "important work" in the area.

The commander of Ukraine's ground forces later said Kyiv's forces were making advances on the outskirts of Bakhmut and were getting closer to a "tactical encirclement" of the city.

Gen Oleksandr Syrskyi added that he had visited troops on the frontline.

The Institute for the Study of War (ISW) appeared to corroborate Gen Syrskyi's claims, writing in a ground report that "geolocated footage" showed a Ukrainian brigade "striking unspecified Russian forces south of Klishchiivka, 7km south-west of Bakhmut".

Analysts say the city is of little strategic value to Moscow, but its capture would be a symbolic victory for Russia after the longest battle of the war in Ukraine so far.

However, when Russia fought fiercely to claim the cities of Severodonetsk and Lysychansk last summer, Ukraine soon reclaimed swathes of territory elsewhere.

It will no doubt be hoping to use a similar strategy for an anticipated counter-offensive this year.

In a separate piece of analysis, the ISW said Wagner had only been able to continue its sustained attack on Bakhmut City after "Russian regular forces" took responsibility for the flanks.

If Mr Prigozhin, Wagner's leader, sticks to his word and withdraws his forces from Bakhmut in the coming days, "Russian conventional forces will be even more unlikely to pursue [other] offensive operations," the ISW added.

The war in Ukraine has dominated the three-day summit of G7 leaders in Japan, with Mr Zelensky meeting with several world leaders to lobby for more support.

His persistence paid off. At the summit, the US announced it would allow its Western allies to supply Ukraine with advanced fighter jets, including American-made F-16s.

However, as yet no country has committed to supplying the jets to Ukraine.

Asked by the BBC how confident he was about getting F-16s from his allies, Mr Zelensky said: "We will be working on that, I'm sure… I cannot tell you how many - this is not a secret, we really don't know."

The BBC also asked him when his delayed spring counter-offensive would begin.

"Russia will feel when we have a counter-offensive," he replied.