Acting U.S. Secretary of Defense Patrick Shanahan speaking at the IISS Shangri-La Dialogue summit in Singapore on June 1, 2019

SINGAPORE — Acting Secretary of Defense Patrick Shanahan called on America's allies in Asia Pacific to invest more in national security — a move that's reminiscent of U.S. President Donald Trump's well-worn script to NATO nations on burden-sharing.

Speaking Saturday at the Shangri-La Dialogue in Singapore, Shanahan highlighted an exhaustive list of U.S. contributions to the region before asking allies to commit to more.

"Our government is devoting significant resources to this mission. This is a massive effort," Shanahan said during his remarks. "Every nation, independent of size, has an important role to play. And like the business of building airplanes, no one nation can go it alone," the former Boeing executive added.

Figures provided by the London-based think tank International Institute for Strategic Studies, put China's 2019 defense spending at $176 billion. That's more than the combined budgets of South Korea, Japan, Australia, Singapore, Indonesia, Thailand, Vietnam, Malaysia and the Philippines.

"People have to invest in themselves. I mean, we are making a sizable investment," Shanahan told a small group of reporters on Friday. "Now, different countries can do more, and some just don't have the means and the resources at the time. So, there is not one size fits all but everybody has a responsibility to invest in security," he added.

When asked about the reaction from partners in the region to a potential spending increase, Shanahan said he expects allies to work with the United States.

"When we are having these conversations it'll be about asking what's appropriate for us to help with and what can they do and I think those are natural conversations," Shanahan said. "I have not found the conversations awkward in the least."