Sen. Ted. Cruz was met with silence during a congressional hearing when he grilled a panel of cybersecurity officials on why China was not sanctioned after the attack on Microsoft and other U.S. companies.

“Let me ask anyone on the panel,” Cruz said Tuesday during the hearing, directing his question at three witnesses. “Do you have an answer as to why the administration has not sanctioned China for repeated cyberattacks over and over and over again against the United States?”

The Texas senator was then met with silence from the officials testifying, who were from the Justice Department, the Cybersecurity and Infrastructure Security Agency and the FBI.

“Well, I think that’s a question that the administration should answer,” he then said. “And showing weakness to China and weakness to Russia only invites more aggression and more cyberattacks attacking our nation.”

The question came after the Biden administration this month blamed China’s Ministry of State Security for the hack against the Microsoft Exchange Server, which compromised tens of thousands of computers around the world.

President Biden was asked last Monday why the U.S. did not sanction China this month, but said officials were still “determining exactly what happened.”

Earlier this year, however, the Biden administration moved to sanction Russia in response to the SolarWinds cyberattack.

“My understanding is that the Chinese government, not unlike the Russian government, is not doing this themselves but are protecting those who are doing it and maybe even accommodating them being able to do it,” Biden said of the difference between Chinese and Russian hacking. “That may be the difference.”