Hillary Clinton's presidential campaign is accusing Donald Trump of caring more about how Britain's historic vote to leave the European Union would benefit his financial bottom line than how it would impact the US economy.
Clinton campaign manager Robby Mook acknowledged parallels between the populist anger and anti-establishment fervour that fuelled the Brexit vote and Mr Trump's rise to the nomination, but said the Republican candidate's reaction showed he was not fit to occupy the White House.
"Hillary Clinton looks at this through the lens of how it's going to affect middle-class families, Donald Trump through the lens of how it will help his bottom line," Mook said on Fox.
In a national television ad released on Sunday, the Clinton campaign featured the wealthy real estate developer's comments on Friday that the fall of the British currency after the Brexit vote could mean more business for his golf course in Turnberry, Scotland, where he was speaking.
"Every president is tested by world events, but Donald Trump thinks about how his golf resort can profit from them," said the 30-second ad.
Besides his currency comments, Mr Trump had praised the Brexit result as an example of people "taking their country back".
He responded to the advertisement on Sunday by saying Ms Clinton, whose staff had said she supported the United Kingdom remaining in the union, had poor judgment.
Global stock markets nosedived on Friday and economic experts warned of a potential global recession after the shocking British vote to pull out of the European Union.
Markets prepared for the possibility of more pain on Monday.
The unexpected outcome quickly reverberated through the November 8 race for the White House on Friday.
Mr Trump called Brexit a model for his insurgent campaign while Clinton said the uncertainty underscores the need for "calm, steady, experienced leadership".
Republican Senator Bob Corker, chairman of the US Senate Foreign Relations Committee, said the Brexit vote highlighted global anxieties about economic stagnation and immigration.
Senate Majority Leader Mitch McConnell, a Kentucky Republican, said the Brexit vote showed people were tired of being dictated to by "unelected bureaucrats in Brussels," and said there were parallels in the United States.
Democratic presidential candidate Bernie Sanders, who built his White House campaign against Clinton around populist proposals to eradicate income inequality, remove big money from politics and rein in Wall Street, said the Brexit vote encapsulated many of those concerns.