"Well, we have said repeatedly that we need to have military communications channels to avoid escalation, to avoid surprise, to avoid mistake and it is unfortunate that the Chinese Defense Ministry has declined to take calls from the U.S. secretary of defense [Lloyd Austin]," Sullivan said during an interview on NBC News’ "Meet the Press" on Sunday.
He specified that high-level contacts are maintained with China and recalled that US Secretary of State Antony Blinken spoke with China's Central Foreign Affairs Office Director Wang Yi at the Munich Security Conference last weekend.
"So, it is not that all lines of communication are cut – are shut off but rather, that we do not have the military-to-military exchanges that we think are necessary to ensure stability," Sullivan said.
Earlier this week, Austin told CNN that he had not spoken to his Chinese counterpart for a "couple of months" and hoped that Wei Fenghe scheduled a phone call.
In early February, Pentagon spokesman Pat Ryder said China had declined a US request to hold a call between Austin and Wei after the US military downed a suspected Chinese surveillance balloon in US airspace. China maintains that the civilian airship was conducting scientific research.