Beijing and Moscow's rapprochement is driven by a strong personal relationship between Putin and Xi, seen as the most powerful Chinese leader since Mao Zedong.
Before the medal ceremony, Putin said the two heads of state had enjoyed "fruitful" talks.
In one phone call, the Canadian PM scoffed at the idea that Canada posed a national security threat to the USA, the administration's pretext for imposing the steep tariffs on imported aluminum and steel.
This is weak. [Valdimir] Putin is not our friend and he is not the President's buddy.
"We will do what is necessary to protect the United States - its business and its workforce", said White House economic adviser Larry Kudlow.
Putin was re-elected to a fourth Kremlin term in March.
"Foreign actors seek to undermine our democratic societies and institutions, our electoral processes, our sovereignty and our security", the G7 leaders said in a statement.
China is mired in tough negotiations with the U.S.to avoid a trade war, while Moscow, Syria, and Ukraine have deep differences with Washington, on multiple diplomatic fronts. You know, whether you like it or not, and it may not be politically correct, but we have a world to run. "Economic globalisation and regional economic integration are the trend of the times", Xi said.
He called Putin his best honest friend and most respected in China. In Mr. Putin's zero-sum calculus, when the United States and Europe founder, Russian Federation benefits.
Mrs May also pushed for action to tackle Russian "dirty money" and work to curtail the movement of Moscow's spies.
According to China Radio International on May 30, citing a Russian media report published that day, 91.3 percent of respondents to the survey consider wisdom Putin's best trait, while 83.4 percent chose to tag the Russian leader as "iron-fisted".
Both sides suggested some progress in NAFTA talks, with White House spokeswoman Sarah Huckabee Sanders saying they were "close to a deal", though adding there was also discussion of a bilateral deal.
"I have been Russia's worst nightmare", Trump claimed, "but with that being said, Russian Federation should be in this meeting".
"The president's support for inviting Russian Federation back into the G-7, just after they meddled in the election to support his campaign, will leave millions of Americans with serious questions and suspicions", Schumer said. Macron said Thursday on Twitter, "The American President may not mind being isolated, but neither do we mind signing a 6 country agreement if need be".
Putin is on a state visit to China, and he will also attend the 18th Shanghai Cooperation Organization (SCO) summit in the eastern Chinese coastal city of Qingdao on Saturday and Sunday.