After widespread shock and condemnation, including from Prime Minister Justin Trudeau, the head of the World Health Organization said Saturday he is "rethinking" his appointment of Zimbabwe President Robert Mugabe as a "goodwill ambassador."

In a new tweet, WHO director-general Tedros Ghebreyesus said that "I'm listening. I hear your concerns. Rethinking the approach in light of WHO values. I will issue a statement as soon as possible."

I’m listening. I hear your concerns. Rethinking the approach in light of WHO values. I will issue a statement as soon as possible —@DrTedros

The 93-year-old Mugabe, the world's oldest head of state, has long been criticized at home for going overseas for medical treatment as Zimbabwe's once-prosperous economy falls apart. Mugabe also faces U.S. and Canadian sanctions over his government's human rights abuses.

Trudeau called the appointment "unacceptable," joining a chorus of widespread condemnation.

The United States and a host of other countries, health and human rights leaders have criticized the appointment of Mugabe who is accused of human rights violations. Trudeau said he was dismayed when he first heard of the appointment.

'Absolutely unacceptable'

"Quite frankly I thought it was a bad April Fool's joke," Trudeau told reporters at a media availability in Edmonton on Saturday.

"It is absolutely unacceptable, absolutely inconceivable that this individual would have a role as a goodwill ambassador."

Canada is making sure its unhappiness with the appointment is being heard, Trudeau said.

"Our diplomats and the folks at Global Affairs are busy making that very, very clear to the international community," he said.

Two dozen organizations — including the World Heart Federation and Cancer Research U.K. — released a statement over the appointment, saying health officials were "shocked and deeply concerned" and citing Mugabe's "long track record of human rights violations."

The United States called the appointment of Mugabe "disappointing."

"This appointment clearly contradicts the United Nations ideals of respect for human rights and human dignity," the State Department said.

Health and human rights leaders chimed in. "The decision to appoint Robert Mugabe as a WHO goodwill ambassador is deeply disappointing and wrong," said Dr. Jeremy Farrar, director of the Wellcome Trust, a major British charitable foundation. "Robert Mugabe fails in every way to represent the values WHO should stand for."

Ireland's health minister, Simon Harris, called the appointment "offensive, bizarre."

"Mugabe corruption decimates Zimbabwe health care," tweeted the head of Human Rights Watch, Kenneth Roth.

With Mugabe on hand, WHO director-general Ghebreyesus announced the appointment at a conference on non-communicable disease in Uruguay this week. Dozens of health groups have reacted with shock.

Tedros, an Ethiopian who took up the post at WHO earlier this year, said Mugabe could use the role "to influence his peers in his region" on the issue. A WHO spokeswoman confirmed the comments to the Associated Press on Friday.

Tedros Ghebreyesus, head of the World Health Organization, says Mugabe was chosen to advocate for better health care throughout Africa. (Fabrice Coffrini/AFP/Getty Images)

In his speech, Tedros described Zimbabwe as "a country that places universal health coverage and health promotion at the centre of its policies to provide health care to all."

Two dozen organizations — including the World Heart Federation, Action Against Smoking and Cancer Research U.K. — released a statement slamming the appointment, saying health officials were "shocked and deeply concerned" and citing his "long track record of human rights violations."

The groups said they had raised their concerns with Tedros on the sidelines of the conference, to no avail. Zimbabwe's government has not commented.

The British government said Mugabe's appointment was "surprising and disappointing" and added that it risked overshadowing the WHO's global work.

Shuttering of hospitals, medical school

The southern African nation once was known as the region's prosperous breadbasket. But in 2008, the charity Physicians for Human Rights released a report documenting failures in Zimbabwe's health system, saying that Mugabe's policies had led to a man-made crisis.

"The government of Robert Mugabe presided over the dramatic reversal of its population's access to food, clean water, basic sanitation and health care," the group concluded. Mugabe's policies led directly to "the shuttering of hospitals and clinics, the closing of its medical school and the beatings of health workers."

Mugabe's frequent overseas travels have cost impoverished Zimbabwe millions of dollars.

The U.S. in 2003 imposed targeted sanctions, a travel ban and an asset freeze against Mugabe and close associates, citing his government's rights abuses and evidence of electoral fraud.

Canada announced sanctions after Zimbabwe's discredited one-candidate presidential runoff election in 2008, including restricting travel, work and study of senior members of Zimbabwe's government within Canada.

UN agencies typically choose celebrities as ambassadors to draw attention to issues of concern, but they hold little actual power.