The World Health Organization says it is reviewing its priorities to reduce costs following US President Donald Trump's withdrawal declaration.

The United States is the largest donor to the WHO.
After the inauguration ceremony on Monday, Trump signed an executive order, stating that his country will withdraw from the body.

The AFP news agency says WHO Director-General Tedros Adhanom Ghebreyesus sent an email to its employees on Thursday, telling them that the US decision has made the organization's financial situation "more acute."

"We are reviewing which activities to prioritize with a reduced resource envelope," he said.

He went on to say that recruitment will be frozen, "except in the most critical areas," and that travel expenses dramatically cut back.

He also said all meetings will be virtual except in exceptional circumstances, and missions to provide technical support to countries should be limited to the most essential.

WHO spokesperson, Christian Lindmeier, described the US decision as a concern for global health. He noted the WHO both provides critical information to the US and receives information from it so as to have "the best possible response" in case of outbreaks.