Russia is behaving like a "rogue nation," former British Prime Minister John Major said Monday.

Speaking at the Credit Suisse Asian Investment Conference in Hong Kong, Major named Russia as one of the economies whose actions affect the international order. The others he cited were the U.S., China and the European Union.

His comments came in the wake of worsening U.K.-Russia relations. Last week, Britain accused Russia of carrying out a nerve agent attack on a former Russian double agent and his daughter on British soil; the Kremlin has denied responsibility.

"Russia is behaving like a rogue nation. She cannot be ignored," Major said in a speech about the geopolitical forces currently at play.

"The British experience suggests Russia will also use murder as a sanction in other countries' territories."

What happened in the U.K. is just one example of Russia's attempt to flex its muscles both "diplomatically and militarily," Major said. Moscow has also had a hand in the Syrian civil war, influenced elections overseas and conducted cyberattacks globally, he said.

All that happened because Russia, under President Vladimir Putin, wants to show that the country still matters on the international stage, Major said.

"The root cause, it seems to me, is clear: Russia was once, as the Soviet Union, a super power, but it is no more. To compensate, Putin wishes his people to see their president standing up to the economic and political super powers of the world."