Andre Berghegger, leading the German Association of Towns and Municipalities, urges national authorities to allocate a minimum of 10 billion euros ($10.9 billion) over the coming decade to bolster urban security, which may involve constructing bunkers.

"During the Cold War, Germany had more than 2,000 bunkers. Of these, only 600 remain, which can protect about 500,000 people. Decommissioned bunkers must urgently be put back into use," Berghegger said in an interview with German media group Funke released on Saturday.

Berghegger emphasized that enhancing the resilience of German cities requires collaborative efforts from the federal government, state governments, and local municipalities. He further underscored the importance of reinstating alerting services and sirens nationwide.

According to a report from German media on June 8, 2023, the country's bomb shelters were found to accommodate only 0.5% of the local population in 2022, a figure that remained unchanged throughout the year.

Read more: US prepared 'rigorously' for nuclear threat in Ukraine since 2022: CNN

On February 29, Russian President Vladimir Putin warned Western nations that sending troops to engage in the war in Ukraine could lead to the risk of provoking a nuclear war.

"We did not start this war in Donbas. As I have said many times, we will do everything to end it, to eradicate Nazism. To fulfill all the tasks of the special military operation. To protect the sovereignty and security of our citizens," he stressed.

Meanwhile, he emphasized that Moscow possesses the capability to target locations in the West with its weapons. The ongoing war in Ukraine has resulted in the most significant crisis in Moscow's relations with the West since the Cuban Missile Crisis of 1962. While Putin has previously expressed concerns about a confrontation between NATO and Russia, his nuclear warning on Thursday marked one of his most unequivocal statements on the matter.

Speaking to legislators and prominent figures within the nation's elite, Putin reiterated his assertion that the West is committed to undermining Russia. He indicated that Western leaders might not grasp the potential peril of their interference, characterizing it as meddling in what he perceives as Russia's internal affairs.

Read more: US in pursuit of B61 nuclear bomb, slammed for ‘running in place’

Before issuing his nuclear warning, Putin specifically mentioned an earlier proposal put forth by French President Emmanuel Macron. The idea involved European NATO members deploying ground troops to Ukraine, but this suggestion was promptly dismissed by the United States, Germany, Britain, and other nations.

"The West provoked the conflict in Ukraine, in the Middle East, in other regions of the world, and continues to lie, without any embarrassment, saying that Russia allegedly intends to attack Europe," the Russian President maintained.

Due to that, "[Western nations] must realize that we also have weapons that can hit targets on their territory. All this really threatens a conflict with the use of nuclear weapons and the destruction of civilization. Don't they get that?!" Putin added.