German Chancellor Olaf Scholz had a one-hour call with Russian President Putin, the first in two years, a German government spokesperson has confirmed.

The Financial Times reported that the Chancellor's spokesman Steffen Hebestreit said that the Social Democratic Party leader "condemned the Russian war of aggression against Ukraine and called on President Putin to end it and withdraw his troops".

The outlet reported that an embattled Mr Scholz also emphasised his country's "steadfast determination" to support Ukraine in its fight against Russian aggression "as long as is necessary".

This comes following claims and counter-claims about Ukraine's ability and willingness to develop a basic nuclear weapon, similar to the "Fat Man" bomb dropped by the US on Nagasaki in 1945.

A think tank - Ukraine's National Institute for Strategic Studies - which advises the Ukrainian government, produced a report claiming that production of a rudimentary device would not be challenging.

"Creating a simple atomic bomb, as the United States did within the framework of the Manhattan Project, would not be a difficult task 80 years later," the report, authored by Oleksii Yizhak, read.

However, the bomb that Ukrainian scientists could create would pack about a tenth of the punch the Fat Man explosive, the report added.

Nevertheless, that power "would be enough to destroy an entire Russian airbase or concentrated military, industrial or logistics installations. The exact nuclear yield would be unpredictable because it would use different isotopes of plutonium".

But today Heorhii Tykhyi, spokesman for the 's foreign ministry, rubbished any suggestion that President Zelensky was considering developing an atomic weapon.

"We do not possess, develop, or intend to acquire nuclear weapons," he said, according to .

" works closely with the IAEA and is fully transparent to its monitoring, which rules out the use of nuclear materials for military purposes."