UNITED NATIONS -- Secretary-General Antonio Guterres enters his second year as the U.N.'s leader in 2018 with a slimmer wallet due to U.S.-inspired budget cuts, part of a growing influence gap that America's rivals may be keen to exploit.

The U.N. adopted a $5.4 billion budget Sunday for the 2018-19 period after extensive negotiations, shaving about $286 million from the total for the previous two years. The final funding decision constitutes a cut of $193 million beyond what was expected for the two-year budget, Guterres' spokesman said in a statement Tuesday, and represents "across-the-board cuts in non-post resources for most departments and offices," referring to non-personnel expenses.

Guterres himself called for "sweeping management reform" in September at a U.S.-hosted event on the sidelines of the General Assembly, as he cited "the hardworking taxpayers who underwrite all the crucial work" of the U.N. But while cutting unnecessary spending was always part of the plan, plenty of work remains to be done -- and the U.S. is not the only player.

A 'step in the right direction'

Nikki Haley, the American ambassador to the U.N., touted Washington's hand in negotiating the budget cuts, calling them "a big step in the right direction" in a news release issued after the adoption. She cited the reduction of "bloated" management functions, stronger support for U.S. priorities and efforts to instill more discipline and accountability as among this year's achievements.

"We will no longer let the generosity of the American people be taken advantage of or remain unchecked," the statement read. "While we are pleased with the results of this year's budget negotiations, you can be sure we'll continue to look at ways to increase the U.N.'s efficiency while protecting our interests."

The U.S. covers 22% of the U.N.'s annual operating budget, serving as the organization's largest donor with gross contributions for 2017 topping $610 million.

This round of budget cuts was not the first time the current American administration has sought savings. Since President Donald Trump took office in January, Washington has looked to slash funding for international cooperation, including a nearly 30% cut to the U.S. Agency for International Development and a $500 million reduction to the U.N. peacekeeping budget.

Filling in the gaps

Richard Gowan, a senior policy fellow at the European Council on Foreign Relations, said Guterres' cultivation of a strong working relationship with Haley has ensured that such cuts, though serious, "have not been fatal."

"Some U.N. officials feel that the secretary-general should be tougher with the U.S.," Gowan told the Nikkei Asian Review. "[B]ut Guterres is a realist and knows he can't afford a massive battle with Washington."

"In general, the U.S. cuts will cause U.N. peace operations some day-to-day inconvenience, but not do real strategic damage," Gowan suggested, though he called a French-backed proposal for a counterterrorism force in Africa's Sahel a "notable victim of U.S. austerity."

European countries and Saudi Arabia helped fill the gap left by the U.S. for that particular proposal, he noted. But across the board, Trump's incremental withdrawal of the U.S. from the world stage has provided space for other countries to step in.

"While Trump and Guterres spent much of 2017 figuring out how to coexist, China, Russia and Saudi Arabia were taking concrete steps to rewrite the ground rules of U.N. diplomacy," Gowan wrote in a recent piece in World Politics Review.

Some experts have suggested that as U.S. influence recedes, China has steadily increased investment in international affairs. The country surpassed Japan to become second-highest contributor to U.N. peacekeeping operations in 2016 and maintained its third-place slot in total budget contributions.

"Whereas Western officials once cast their Chinese counterparts as cautious and inexperienced, many now speak admiringly of their 'flexibility' and commitment to stability, in a sharp break with Russia's crude assertiveness," Gowan wrote, noting China's proven willingness to compromise in the Security Council on North Korea sanctions.

"[W]hile Trump has veered between weakening the U.N. and working with it, China and Russia have begun to reshape the institution by asserting their capacity to influence the main crises of the day, albeit with different styles and methods," Gowan wrote.