President Donald Trump on Wednesday said it is "common sense" to bring Russia back into the G7, despite Moscow's expulsion from the club after invading part of Ukraine.

Speaking to Fox News radio, Trump said that the G7 countries -- Britain, Canada, France, Germany, Italy, Japan and the United States -- need Russian President Vladimir Putin back in a G8 format, regardless of his behavior.

"It's not a question of what's he done, it's a question of common sense. So we have a G7: he's not there, half of the meeting's devoted to Russia, and if he was there, it would be much easier to solve," Trump said.

"The problem is, many of the things that we talk about are about Putin, so we're just sitting around wasting time, because then you have to finish your meeting and somebody has to call Putin," he said.

"I say, have him in the room. It used to be the G8. I don't say deserving or not deserving, I say common sense."

Moscow was suspended indefinitely from the G8 after it invaded the Crimea region of Ukraine in 2014, then declared the territory part of Russia.

The Kremlin simultaneously supported an ongoing armed rebellion against Ukraine's government in the east of the country.

The episode was the final straw in the long-running deterioration of the relationship between Western powers and Putin's Russia.

In 2008, Putin ordered troops into two regions of Western-backed Georgia that Moscow supports as independent from the Georgian government. The Russian government is also accused by European authorities of being behind a series of assassinations across Europe, including using biological and radioactive poisons in Britain.

Trump, who is highly critical of the NATO military alliance and describes the European Union as a hostile trading competitor, has pushed repeatedly for a softer approach to Russia.

After his hastily conceived plans for hosting an in-person G7 summit in Washington this month fell through, amid the ongoing coronavirus pandemic, he abruptly announced Saturday that he wants to reform the group entirely, bringing Russia and other countries to a meeting later this year.

Trump called the G7 -- long seen as a key diplomatic gathering for the richest, most advanced democracies -- "a very outdated group of countries."

Washington's G7 partners are pushing back against the idea of transforming the group.

EU foreign affairs high representative Josep Borrell said Tuesday that while Trump -- as this year's G7 chair -- could invite Russia with guest status, he does not have the power to change "the format on a permanent basis."

Canadian Prime Minister Justin Trudeau on Monday said he opposed Moscow reentering the fold.

"Russia was excluded from the G7 after it invaded Crimea a number of years ago," Trudeau told reporters. 

"Its continued disrespect and flaunting of international rules and norms is why it remains outside of the G7 and will continue to remain out," he added.