U.S. Sen. Lindsey Graham says the response by the United States to China detaining two Canadians in apparent retaliation for the arrest of a Chinese Huawei executive has not been strong enough.

Graham also told Munich Security Conference delegates Friday 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.

Graham says President Donald Trump "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."

Canadian Foreign Minister Chrystia Freeland mouthed the words "thank you" to Graham.