Guterres will travel to Washington next week to make the case directly to US members of Congress who have the power to amend President Donald Trump's budget proposals.

Last month, the US State Department laid out plans to slash Washington's budget for diplomacy and foreign aid by more than 30 percent, including a dramatic cut of 60 percent to US funding for peacekeeping missions.

The United States is the biggest contributor to the United Nations, paying 22 percent of the $5.4 billion core budget and 28.5 per cent of the $7.9 billion peacekeeping budget.

"The proposal of budget that was presented to the Congress would create an insolvable problem to the management of the UN," Guterres told a news conference at UN headquarters.

"The process is still in the Congress and I will soon be going to Washington," he added.

Guterres has no plans to visit Trump at the White House during the June 27-29 visit, or hold talks with US Secretary of State Rex Tillerson.

He will meet with key players on Capitol Hill: Republican speaker Paul Ryan, Nancy Pelosi, the Democratic leader of the House of Representatives,Republican Senator Marco Rubio and members of the foreign relations and appropriations committees in both houses, among others.