RUSSIA’S nuclear arsenal is paralysing the international response to the invasion of Ukraine, an Essex University expert has claimed.

Professor Natasha Lindstaedt’s comments come after a flood of condemnations of the attack from across the world.

Today Russian troops pressed on with their invasion of Ukraine to the outskirts of the capital after unleashing air strikes on cities and military bases.

Explosions sounded before dawn and gunfire was later heard near the government quarter as Ukraine’s president pleaded for international help to fend off the attack which could topple his democratically elected government.

Professor Lindstaedt, who is a renowned international relations expert in the Department of Government, said:“Putin’s brazen full-scale invasion of Ukraine is the absolute worst-case scenario and will lead to a human security crisis and a long-protracted conflict.

“It is certain that Putin will annex part of eastern Ukraine and occupy the country for an extended period of time.

“Sanctions are necessary but they will not compel Putin to change course. They will only hurt the Russian population, which is still oppressed and fed false information.”

Following the attack, Prime Minister Boris Johnson has unveiled the “largest and most severe” package of UK sanctions Russia has faced to punish Vladimir Putin.

They included measures to hit five more oligarchs, including the Russian president’s former son-in-law, ban Aeroflot planes from landing in the UK and to freeze the assets of all major Russian banks, Prof Lindstaedt added: “Because Russia is a nuclear power, the international community has few tools at its disposal - escalation or getting involved is too risky, and Putin has showed he has absolutely no concern what the world thinks, or his own population.

“This invasion shows that Putin is increasingly isolated in his decision making and surrounded by sycophants, incapable of offering sound advice.”

A spokesman for the University of Essex has said:” We have a small number of students from Ukraine and Russia and we are contacting them individually to offer any help and support we can at this difficult and uncertain time.”

In retaliation to the British ban, Russian civil aviation authority Rosaviatsiya has banned UK flights to and over Russia.