File Photo: A man puts a letter into a mailbox outside a post office in New York, the United States, August 6, 2009. (Xinhua/Gu Xinrong)

WASHINGTON, Oct. 17 (Xinhua) -- The U.S. Department of State will file notice that the United States will withdraw from the Universal Postal Union (UPU), an international body of the United Nations (UN), the White House announced on Wednesday.

"This will begin a one-year withdrawal process, as set forth in the UPU Constitution," the White House said, adding the Department of State will seek to "negotiate bilateral and multilateral agreements" that resolve the problems related to reform the terms of the postal treaty.

"If negotiations are successful, the Administration is prepared to rescind the notice of withdrawal and remain in the UPU," said the White House.

The UPU, which consists of 192 members and is located in Switzerland, sets shipping rates for international mail in a way that guarantees lower prices for shipments from developing economies and higher rates for those from advanced economies.

The Donald Trump administration believed that the current structure of international mailing rates benefit some developing economies, while putting American small businesses and manufacturers at a severe competitive disadvantage.

The administration had sought to renegotiate the postal rates, known as terminal dues, at a summit of the UPU in Addis Ababa, Ethiopia last month, but was rebuffed by other countries, senior White House officials on Wednesday told reporters in a conference call.

Now the administration plans to set its own "self-declared" international postal rates as it moves to pull out of the 144-year-old international postal body.

"The President concurs with the Department of State's recommendation to adopt self-declared rates for terminal dues as soon as practical, and no later than January 1, 2020," the White House said.

It's not clear whether U.S. consumers will face higher prices reflecting new shipping rates if the Untied States formally withdraws from the UPU.

The move against the UPU represented another U.S. departure from multinational organizations and treaties, after it pulled out of the Paris climate accord, the UN Global Compact on Migration, the UN culture and education body UNESCO, the UN Human Rights Council, as well as the Iran nuclear deal.