WASHINGTON -- The United States enjoys a range of benefits from maintaining its military presence in South Korea and Japan, US officials said Tuesday.

The officials from the Government Accountability Office (GAO) also suggested while some of those benefits may not be quantified, they could easily justify the associated costs.

"There are important, intangible benefits coming from the military and interoperability issues. I mean it's not an insignificant benefit," said Diana Maurer, director of defense capabilities and management at GAO.

GAO is an independent, federal legislative branch agency that supports congressional oversight of the US government.

Maurer explained the interoperability of the US military and its South Korean and Japanese counterparts often lead to large purchases of US weapons systems and military equipment by the US allies, which " makes it easier to exercise together, makes it easier to train together."

"So there are intangible benefits as well as intangible costs on both sides of the ledger when it comes to the military aspects of our relationship," she told a webinar hosted by the East-West Center in Washington.

Tuesday's webinar was based on a GAO report on "Benefits and Costs Associated with the US Military Presence in Japan and South Korea."

In the report, published last Wednesday, GAO listed six benefits to US national security derived from US military presence in the two Asian countries.

They are -- regional security and stability, denuclearization and nonproliferation, defense capability and interoperability, strong alliances, contingency responses and a free and open Indo-Pacific.

While the report does not offer any clear conclusion on the net benefit of the US military presence in Asia compared to its costs, it does provide how much money the US government has obligated in the two nations over the 2016-2019 period and how much the two host nations have contributed over the same period in terms of dollar values.

For the cited period, the US obligated $20.9 billion in Japan and $13.4 billion in South Korea, according to the report.

While Japan and South Korea provided $12.6 billion and $5.8 billion, respectively, in direct financial contributions over the period, they also provided a great amount of support in indirect contributions that included financial support for local communities that house US troops, and in South Korea, for instance, the cost of building Camp Humphreys, the largest US base outside of US mainland.

The GAO officials explained the difference between financial contributions by South Korea and Japan comes largely from the difference in the number of US troops stationed in each country.

Japan currently hosts around 55,000 US soldiers on its soil while South Korea has about 28,500 US troops stationed.

"When we moved into the realm of indirect costs, (we) certainly recognized that there are important contributions made by Japan and South Korea that are indirect in nature. We didn't have good information sources within the US government to get dollars around those figures," Maurer said at the webinar.

Unlike the indirect contributions, however, the intangible benefits the US enjoys from its military presence in the Asian countries cannot and should not be in dollar values, the GAO officials said.

"Initially, we were interested in, 'Hey, to what extent might we be able to quantify these different benefits? Can we assign a dollar value to these?" said Jonathan Adams, defense capabilities and management analyst at GAO.

"And we heard time and again from experts that A, that's probably not possible, and B, they weren't even sure that it was wise to do that because it kind of played into a transactional view to your point of our alliances and that on some level, fundamentally, the benefits derived from our forward presence in these two nations can't and perhaps shouldn't be quantified," he added.

Jason Blair, director of international affairs and trade at GAO, agreed.

"We just have to start with the admission that we don't enter into alliances because we think we're going to come out winners in the counting the dollars and cents," he said.

"We do it for other, larger strategic purposes ... we do it because we have a long term vested interest as we do with these two important partners." (Yonhap)