Tensions were heightened on Saturday when Russia’s ministry of defence alleged that an American submarine sailed into Russian waters.

According to Mirror UK, Russia claimed it detected the submarine near the Kuril Islands in the Pacific and deployed its war ships to chase it out.

This development has sparked global unease, as many fear the world is on the brink of war.

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However, Captain Kyle Raines, US military spokesman, issued a statement denying Russia’s claims.

 “There is no truth to the Russian claims of our operations in their territorial waters,” Raines said.

“I will not comment on the precise location of our submarines, but we do fly, sail, and operate safely in international waters.”

Russia said the US vessel ignored orders to surface or leave the area, leading to the ship using “appropriate means” to drive it away.

The US embassy’s military attaché was also summoned by Russia’s defence ministry over the allegations.

“The U.S. submarine… left Russian territorial waters at maximum speed,” the Russian defence ministry said in it’s statement.

“We are aware of press reporting about an alleged naval incident in the Pacific. We cannot confirm the details of these reports at this time,” a spokesman for the Pentagon also stated.

Russia has more than 130,000 troops stationed near its border withUkraine and has sent troops to exercises in nearby Belarus.

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On Saturday, Vladimir Putin, Russian Prime Minister, spoke on the phone with Joe Biden, his American counterpart. Biden warned that the US would ‘respond decisively and impose swift and severe costs on Russia’ should it invade Ukraine.

American sources hinted that Russia’s invasion of Ukraine could start as early as Wednesday.

The US, the UK, and some other countries have also advised their citizens to leave Ukraine just as diplomatic talks continue to stalemate.

The current tensions come eight years after Russia annexed Ukraine’s southern Crimea peninsula. Since then, Ukraine’s military has been locked in a war with Russian-backed rebels near Russia’s borders.