Canadian Prime Minister Justin Trudeau said he told Trump that readmitting Russian Federation 'is not something that we are even remotely looking at at this time'.
"Russia is more often than not trying deliberately to be a strategic rival, to deliberately counter the good things we're trying to achieve in the world than for no other reason than to just counter them".
"Trump fulfils his pre-election promises", he said.
Trump has repeatedly put himself at odds with practically the entire United States political and security establishment over Russian meddling in the 2016 Presidential Election.
In a joint statement, then-President Barack Obama and other world leaders condemned Russia's actions as "violat [ing] the principles upon which the worldwide system is built".
Washington's relations with Moscow have been particularly strained in the wake of the 2016 US presidential election, which USA intelligence agencies said was targeted by Russian Federation.
Tensions mounted between the Trump administration and fellow G7 members Canada, Germany and France when the U.S. imposed steep tariffs on imported metals from the countries.
The president repeated his tough stance on tariffs, saying allies had been "taking advantage" of the U.S. on trade.
At the same time he downplayed tensions at the acrimonious G7 meeting in Quebec City, after Trump disowned the joint summit statement and lambasted Canadian Prime Minister Justin Trudeau.
Donilon also criticized Trump for isolating the United States at a summit where it used to be the leader. On the National Security and Defense section of his "Promises Kept" website, the Trump re-election campaign highlights almost two-dozen separate actions the Trump administration has taken against Russian Federation "to punish those who seek to undermine American democracy and stability".
He said that the USA exit from the nuclear deal warrants an "important and serious discussion between our two countries". "European Union treats us very unfairly, Canada very unfairly, Mexico very unfairly".
Iranian President Hassan Rouhani on Sunday criticized US "unliteralism" in withdrawing from the Iran nuclear deal and said he appreciated efforts by China and Russian Federation to maintain the agreement.
The Russian president, Vladimir Putin, has said he is happy to meet with Donald Trump once Washington is ready to hold the summit and welcomed the USA president's call to bring Moscow back into the G7 group of leading industrialised nations.
Putin indicated that he did not like "a lot" of the U.S. authorities' decisions but praised Trump for his consistency. While his administration has hit the country with sanctions over its "malign activity around the globe", Trump himself has appeared reluctant to punish Putin.
Trump said, "I have been Russia's worst nightmare", Trump claimed, "but with that being said, Russian Federation should be in this meeting".
Critics said the growing USA isolation is risky at a time when Trump is making diplomatic overtures with North Korea and in the Middle East and could use the support of allies.