The United Arab Emirates Foreign Ministry has confirmed in a statement that former Afghanistan President Ashraf Ghani is in the United Arab Emirates, days after fleeing his home country.

Ghani and his family left Kabul on Sunday as the Taliban surged closer to the presidential palace. The Taliban ultimately overtook the building and has claimed the formation of the "Islamic Emirate of Afghanistan."

Days removed from the Taliban's takeover of Kabul and after a lengthy news conference with national security adviser Jake Sullivan, there is still little clarity on how conditions degraded so quickly in Afghanistan.

When ABC News Correspondent Stephanie Ramos asked Sullivan about reports that Biden administration officials were informed the Taliban could overwhelm the country, the national security adviser denied seeing it.

"I'm not actually familiar with the intelligence assessments you're describing," said Sullivan.

The administration plans to conduct an evaluation of the calamity once evacuations are completed.

"We'll look at everything that happened, in this entire operation, from start to finish, and the areas of improvement where we can do better," Sullivan told reporters Tuesday. "Where we can find holes or weaknesses and plug them as we go forward" that analysis will be shared.

Lawmakers are also putting pressure on the Biden administration for answers. Republicans on the House Armed Services Committee penned a letter to Biden demanding withdrawal plan details, plainly accusing the president of not having a concrete plan.

"For months, we have been asking you for a plan on your withdrawal from Afghanistan. You failed to provide us with one and based on the horrific events currently unfolding in Afghanistan, we are confident that we never received your plan because you never had one," the letter reads. "The security and humanitarian crisis now unfolding in Afghanistan could have been avoided if you had done any planning."

-ABC News' Deputy Political Director Averi Harper

Months of violence in Afghanistan "have taken a heavy toll" on the country's people and fragile health system, the World Health Organization warned Wednesday.

"As a result of the recent conflict, trauma injuries have increased, requiring scaled up emergency medical and surgical services," Dr. Ahmed Al-Mandhari, the WHO's regional director for the Eastern Mediterranean, said in a statement.

In July, some 13,897 conflict-related trauma cases were received at 70 WHO-supported health facilities in Afghanistan, compared with 4,057 cases during the same time last year, according to the WHO.

In Kabul and other areas where people have fled to seek safety and shelter, field reports indicate rising cases of diarrhea, malnutrition, high blood pressure, COVID-19-like symptoms and reproductive health complications. The country's hospitals were already facing shortages in essential supplies amid the coronavirus pandemic, Al-Mandhari said.

Attacks on health care infrastructure and staff also remain a major challenge. From January to July, 26 health facilities and 31 health care workers were affected, while 12 workers were killed, according to the WHO.

"Delays and disruptions to health care will increase the risk of disease outbreaks and prevent some of the most vulnerable groups from seeking life-saving health care," Al-Mandhari said. "There is an immediate need to ensure continuity of health services across the country, with a focus on ensuring women have access to female health workers."

"The people of Afghanistan need support and solidarity today more than ever," he added. "The gains of the past 20 years cannot be turned back."

Biden will sit down with ABC News' George Stephanopoulos one-on-one on Wednesday at the White House for the president's first interview since the withdrawal from Afghanistan.

The interview will air on ABC's "World News Tonight" on Wednesday and "Good Morning America" on Thursday.