A US State Department report on Friday criticized the handling of the 2021 evacuation from Afghanistan, saying decisions by President Joe Biden and his predecessor Donald Trump to withdraw troops had "serious consequences for the viability" and security of the former US-backed government.

Adverse findings in the report also reflected badly on Secretary of State Antony Blinken, without naming him. They included the department's failure to expand its crisis-management task force as the Islamic Emirate of Afghanistan advanced on Kabul in August 2021 and the lack of a senior diplomat "to oversee all elements of the crisis response."

"Naming a 7th floor principal ... would have improved coordination across different lines of effort," said the report, referring to the State Department's top floor where Blinken and senior diplomats have offices, Reuters reported.

The review, and a similar Pentagon study, contributed to a report released by the White House in April. But the State Department review's critical findings were not reflected in the White House report.

White House press secretary Karine Jean-Pierre defended Biden's handling of the Afghan pullout.

"He had to make a decision," she told reporters on Friday. The United States had poured "billions of dollars into a war with no end in sight" and that "he wanted to stop that, he wanted to end that," she said.

Steven Cheung, a spokesman for Trump, wrote in an email: "There’s only one person responsible for the disastrous pullout of Afghanistan — Joe Biden,"

The White House report effectively blamed the chaotic US pullout and evacuation operation on a lack of planning and troop reduction rounds by Trump following a 2020 deal with the Taliban to withdraw US forces.

"I can't speak to that internal coordination piece and how the administration settled on the core conclusions that it presented" in April, a senior State Department official said.

The official, briefing reporters on condition of anonymity, declined to say why the review dated March 2022 was withheld from release until the eve of the July 4 holiday weekend, Reuters reported.

The State Department released 24 pages of an 85-page After Action Report - the rest remained classified - on its handling of the evacuation operation launched as the last US-led international forces departed after 20 years of backing successive Kabul governments against the Taliban.

While those decisions were outside its scope, the review said that "during both administrations there was insufficient senior-level consideration of worst-case scenarios and how quickly those might follow."

A White House spokesperson disputed that conclusion. He pointed to a White House report finding that there were extensive meetings and tabletop exercises to explore evacuation scenarios as part of the planning process, including contingencies "actually worse than the worst-case predictions."

The State Department review said department planning "was hindered" because it was "unclear" which senior official "had the lead."

Senior administration officials also failed to make "clear decisions regarding the universe of at-risk Afghans" to be included in the evacuation by the time it started nor had they determined where Afghan evacuees would be taken, it said.

Preparation and planning "were inhibited" by the Biden administration's reluctance to take steps that could signal a loss of confidence in the Kabul government "and thus contribute to its collapse," the review found.