Graham also told Munich Security Conference delegates the international reaction to China's arrest of ex-diplomat Michael Kovrig and entrepreneur Michael Spavor hasn't been enough to persuade China that its apparent use of hostage diplomacy won't be tolerated.
"The president has been tough on China but this is one area where I think we need to make a more definitive statement, because the two people arrested in China had nothing to do with the rule of law. It was just grabbing two Canadians," Graham said.
Canadian Foreign Minister Chrystia Freeland, who appeared on the panel with Graham, mouthed the words "thank you" to Graham after he said it. Roland Paris, one of the delegates and a former foreign policy adviser to Canadian Prime Minister Justin Trudeau, asked Graham about it.
Meng is the chief financial officer of the Chinese tech giant Huawei and the daughter of its founder. The U.S. wants her extradited to face charges that she committed fraud by misleading banks about Huawei's business dealings in Iran.
China also re-sentenced a convicted Canadian drug smuggler to death after the Meng arrest as part of an apparent campaign of intimidation and retribution against Canada.
Beijing threatened grave consequences for America's neighbor and longtime ally after Meng was arrested at Vancouver's airport.
Canada has embarked on a campaign with allies to win the release of Kovrig and Spavor and many countries have issued statements in support.
"These are human beings and they only thing they did was be Canadian in China," Freeland said. Freeland said she would be grateful if more countries spoke out.
"We will all be stronger and safer if we all can do that for each other," she said. "We can't descend to a might makes right world and that's especially essentially for middle powers."
The two Canadians were detained on vague allegations of "engaging in activities that endanger the national security" of China. They remain locked up without access to lawyers.
Meng is out on bail in Canada and awaiting extradition proceedings.
Associated Press writer Rob Gillies in Toronto contributed to this report.