Moscow, Aug 17 (IANS): Jailed Kremlin critic Alexei Navalny has called on the West to impose tougher sanctions on Russian oligarchs, as Moscow's war on Ukraine continues unabated.

"Let us not forget: sanctions are needed to force the aggressor to stop the war. To put pressure on him. And there are complex solutions here like the oil and gas embargo. But then there are really simple ones: personal sanctions," dpa news agency quoted Navalny as saying in an appeal from the prison camp where he is serving a lengthy sentence.

"They don't require anything but political will."

In a series of tweets, Navalny criticized the fact that while the head of state-owned Rosneft, Igor Sechin, is on an EU sanctions list, the head of energy giant Gazprom, Alexei Miller, is not.

Billionaire Roman Abramovich, a former English football club Chelsea FC, was not included on a US sanctions list, for example, he said.

Of the 200 people listed as the richest Russians bz Forbes magazine, barely a quarter are on Western sanctions lists, Navalny said.

Navalny is currently serving a nine-year prison sentence in a penal colony for alleged fraud.

The Russian judiciary is widely seen as controlled by the Kremlin, and has been slammed for its arbitrary rulings by human rights activists.

The dissident is viewed as a political prisoner, with his jailing criticized as retribution for his ongoing criticism of the Russian authorities.

Navalny narrowly survived an attempt to poison him with the chemical agent Novichok in August 2020, for which he blames President Vladimir Putin.