Russia’s parliament gave its final seal of approval to constitutional changes potentially allowing President Vladimir Putin to stay in power for years to come, removing a key source of uncertainty about Russia’s political future and likely ensuring that Moscow will continue to challenge the U.S. on the world stage. The State Duma, the lower house of parliament, Wednesday approved amendments to the law that would allow Mr. Putin to serve another two six-year terms until 2036. According to term limits currently in force, Mr. Putin wouldn’t be allowed to run again after his current stint ends in 2024. A nationwide vote on the amendments is set for April 22.

At the helm for more than two decades, the move helps shore up Mr. Putin’s control over political and social life in Russia and could make him the longest-ruling leader in Russia’s modern history, surpassing Joseph Stalin. If he remains in power, Mr. Putin is likely to carry on for years with his bid to revive Russia’s global clout and challenge what he has denounced as a U.S.-led world order.

In recent years, Mr. Putin’s adventurism abroad has made Russia a key player in countries suffering from conflict or political upheaval, such as Syria and Venezuela. This month, Russia’s breakup with the Saudi Arabia-led Organization of the Petroleum Exporting Countries—an informal alliance dubbed OPEC+—sent oil prices tumbling and rattled financial markets.