WASHINGTON: US Secretary of State Antony Blinken promised Wednesday to welcome and respond to all internal dissent and to review any missteps in the evacuation from Afghanistan.

In a speech on the modernization of the State Department, the top US diplomat also laid out plans for a new cyber bureau to handle rising hacking threats and a greater focus on global challenges such as climate change and public health.

Speaking at the Foreign Service Institute, the State Department's training center in suburban Washington, Blinken said that he has "revitalized" the agency's celebrated "dissent channel."

"Dissent is patriotic. And it should be not just protected; it should be and will be welcomed," Blinken said.

"I'm reading and responding to every dissent that comes through the channel. And I hope that the dissent channel will encourage a culture of constructive, professional dissent more broadly throughout the State Department, because dissent makes us stronger."

In July, diplomats sent a dissent cable to Blinken warning that Afghanistan's government was collapsing more quickly than anticipated and urging an immediate airlift.

The Biden administration responded by stepping up visas for vulnerable Afghans but it did not start its massive airlift until weeks later when it became clear the Taliban was taking over.

Blinken said he had ordered a series of internal reviews on how the State Department could have handled the operation differently.

"We will not let this opportunity to learn and do better pass us by," Blinken said.

Biden administration officials say that the former government of President Ashraf Ghani had discouraged an airlift, fearing it would show vulnerability.

The dissent channel was set up during the Vietnam War by then secretary of state Dean Rusk to provide a sanctioned way for diplomats -- many of whom were deployed -- to share views with superiors.

The results have been mixed. In one of the early examples, foreign service officers protested then president Richard Nixon's planned invasion of Cambodia, which went ahead.