US President Donald Trump has been slammed by world leaders for announcing a temporary halt in funding to the World Health Organization (WHO) pending a review. Trump accused the UN health body of "covering up" the coronavirus pandemic and inadequately responding to the spread of COVID-19.

Here are the key things you need to know about this decision and its repercussions.

What is the WHO?

Founded on April 7, 1948, the WHO is a specialized agency of the United Nations that is responsible for global public health. With 194 member states, WHO is headquartered in Geneva, Switzerland. The agency has six regional offices as well as 150 national offices.

Read more: World Health Day: What does the WHO do?

In addition to providing emergency assistance in its mission to foster the best health possible for citizens around the globe, it also monitors global health trends, especially as regards diet and sanitation.

Responsible for declaring global health emergencies, like in 2009 with the swine flu, 2014 and 2019 with Ebola, the WHO declared the novel coronavirus SARS-CoV-2 and the disease it causes, COVID-19, a Public Health Emergency of International Concern on 30 January 2020.

How do WHO finances work?

The WHO's 2020-2021 operating budget was $4.8 billion (€4.8 billion), one-fifth of which was covered by statutory assessed contributions from the UN's 194 member states. The amount paid by different countries is dependent on the size of their economies.

The rest of the WHO's budget is financed by donations from countries, philanthropic foundations, UN institutions, non-governmental organizations (NGOs) and private donors, on a voluntary basis.

Out of the 2018-2019 budget of $5.62 billion, $4.3 billion was in specified voluntary contributions. The US was the biggest contributor (14.67%), followed by the Bill and Melinda Gates Foundation (9.76%), the GAVI vaccines alliance (8.39%), Britain (7.79%) and Germany (5.68%).

China's contribution stood at 0.21% of the total, lagging behind Luxembourg (0.3%) and Pakistan (0.36%).

How much did the United States contribute?

Under the budget for 2018 and 2019, the US contributed $553.1 million, which made up 14.67% of the total specified voluntary contributions to the WHO. In terms of statutory contributions, the United States contributed $237 million (~25%), while China contributed $76 million (8%).

Why has the US halted funding to the WHO?

Trump announced the freeze in funding to the WHO over allegations that the agency had not done its job to assess the coronavirus outbreak in China and prevent its spread. He added that the WHO had "failed in its basic duty and must be held accountable," and that the agency knowingly stood behind China's "disinformation" about the virus.

Trump said that the US would conduct a review of the WHO's role, which could take between 60 to 90 days. However, there was no indication of how the suspension will be executed during the "very thorough investigation."

What does this mean for the WHO?

WHO chief Tedros Adhanom Ghebreyesus said that the organization "regrets" President Trump's decision and "hoped" that it would be reversed.

"The United States of America has been a long-standing and generous friend of the WHO and we hope it will continue to be so," Tedros said. "We regret the decision of the President of the United States to order a halt in the funding to the WHO."

"When we are divided the virus exploits the cracks between us."

However, the agency was still in the process of assessing the impact of this decision and would "try to fill any gaps with partners," Tedros added.

Close to $1 billion of the new WHO budget was earmarked for operations across Africa, where the organization is attempting to tackle multiple vaccine-preventable diseases. In addition to this, the WHO's polio eradication program also received sizeable contributions from the United States.

With the freezing of funds, the agency will need to receive additional funding from other partners to meet its goals. With economies across the world suffering because of the coronavirus pandemic, securing additional funds may be a challenge.

Support for the WHO, however, has started pouring in.

The Bill & Melinda Gates Foundation announced an additional $150 million to help the fight against coronavirus on Wednesday. Melinda Gates said the WHO was "exactly the organization that can deal with this pandemic."

How has the rest of the world reacted?

Trump's allegations that the agency had covered up the initial coronavirus outbreak have been met with widespread opposition from politicians, diplomats and medical professionals.

United Nations Secretary-General Antonio Guterres said it was "not the time" to reduce funding to the agency, which is at the forefront of international efforts to stem the spread of coronavirus.

Germany's Foreign Minister Heiko Maas also rejected Donald Trump's move, saying that the UN, and ''especially the underfunded WHO,'' were the best institutions to ''strengthen the development and distribution of tests and a vaccine.''

Both China and Russia, facing criticism over their handling of the pandemic, expressed concern over the US decision.

"This US decision will weaken WHO's capacities and undermine the international cooperation against the epidemic," Chinese official Zhao Lijian told a press briefing.

Russian Foreign Minister Sergey Lavrov also said that the world needs to "refrain from finger-pointing" and fight the common peril together. "I would warn against attempts to politicize the coronavirus outbreak, and that refers not only to the WHO's role, but also to accusations aired against certain countries," he added.

"To protect ourselves locally in Germany or in America, we have to act globally," former UK Prime Minister Gordon Brown told DW. "And if this disease has a second and third round in Africa or in the developing world and then comes back to the West, then we'll be to blame for not helping those African countries that the WHO is intent on supporting."

Within the US, there has been a significant backlash from politicians and healthcare experts.

US House Speaker Nancy Pelosi warned Americans to ''ignore the lies'' and ''insist on the truth'' regarding the US response to the coronavirus pandemic.

"The President's halting of funding to the WHO as it leads the global fight against the coronavirus pandemic is senseless," she said in a statement. "This decision is dangerous, illegal and will be swiftly challenged."

Dr. Patrice Harris, the president of the American Medical Association, also slammed the move to halt funding, calling it "a dangerous step in the wrong direction that will not make defeating COVID-19 easier."

The United States currently has the highest number of cases and a higher death toll than any other country in the world, with more than 630,000 infections and close to 28,000 deaths.

see/se (Reuters, AP, AFP)