U.S. President-elect Donald Trump is expected to select Sen. Marco Rubio to be his secretary of state and Rep. Mike Waltz to be national security adviser — picks that will likely see the second Trump White House get even more hawkish on China but prove reassuring for American allies such as Japan.

The pick of Rubio to be the top U.S. diplomat was first reported Monday by The New York Times, which quoted three unidentified sources. The sources said that while Trump could still change his mind at the last minute, he appeared to have settled on Rubio as of Monday.

A senior member of the powerful Senate foreign relations and intelligence committees, Rubio has long been an advocate for a more muscular approach to Beijing.

These views were highlighted in a September report authored by his office that opened by calling China “the most powerful adversary the United States has faced in living memory.”

But he has also stressed the importance of the U.S.-Japan alliance and downplayed comments from Trump earlier this year denigrating NATO and encouraging Russia “to do whatever the hell they want” to member countries that did not meet defense spending targets.

Those remarks stoked concern in Tokyo that Trump might once again approach the U.S. alliance with Japan from a more transactional point of view — even after the ostensibly pacifist country ramped up defense spending to unprecedented levels.

Trump has long viewed U.S. alliances with disdain, reportedly even demanding as late as 2019 that Japan pay $8 billion to cover costs for hosting American troops — a massive jump from the $1.8 billion it had paid that fiscal year.

In a sign that Rubio could provide a moderating influence on Trump’s more transactional views, Congress last year passed a bill coauthored by the Florida senator that required any presidential decision to exit NATO have either two-thirds Senate approval or be authorized through an act of Congress.

While Rubio’s views on foreign policy have grown closer to Trump’s as the president-elect has cemented his grip on the Republican Party, the Florida senator has continued to voice support for the U.S.-Japan alliance, especially as tensions in Washington’s rivalry with Beijing surge.

“Japan’s role as a key ally in matters of security, intelligence and economic affairs cannot be overstated,” he said in April, ahead of then-Prime Minister Fumio Kishida’s visit to Washington.

Waltz, like Rubio, is widely seen as one of the most hawkish Washington lawmakers on China, and is also a member of the House of Representatives’ Republican China Task Force. As the next national security adviser, Waltz would be the principal adviser to the president on all national security issues. His impending appointment to the post, which does not require Senate approval, was also reported by U.S. media on Monday.

A retired U.S. Army colonel who fought in the war in Afghanistan, Waltz previously worked as a defense policy director at the Pentagon under Defense Secretaries Donald Rumsfeld and Robert Gates, and advised the White House on defense-related policies.

In Congress, he sponsored bills to reduce American reliance on the imports of critical minerals from China and to prevent Chinese espionage in U.S. universities, according to his congressional website.

Both Rubio and Waltz have been vocal in strengthening the United States’ shipbuilding capabilities through cooperation with allies amid what they say is a growing threat from China’s expanding naval presence in the Indo-Pacific region.

In a congressional report the pair coauthored with two others in April, they stressed the need for a national maritime strategy to “reverse the decline of American maritime power.” Such a strategy would outline the need to involve treaty allies to share the cost of shipbuilding and critical maritime projects, as well as to expand domestic shipbuilding and insource capabilities to the U.S. market.

“We cannot continue to allow the People’s Republic of China to increasingly grasp control of freedom of navigation on the high seas, international ocean shipping, and the critical maritime infrastructure necessary to maintain global security and the American way of life,” the report reads.

At an event hosted by the Center for Strategic and International Studies think tank in September, Waltz also suggested the next administration direct part of the funds from a $1.2 trillion infrastructure bill to the shipbuilding industry.

Meanwhile, Waltz has signaled an alignment with Trump on demanding that U.S. allies dole out more cash for their defense — something likely to cause headaches among partners in Europe and the Indo-Pacific region.

“Until Trump began the public drum beat for defense cost-sharing, European politicians were quite comfortable with American taxpayers subsidizing their defense so they can pay for their social welfare programs,” Waltz wrote in a February op-ed on his website praising the former president for pushing NATO members to meet their 2% of gross domestic product defense spending commitment.

“Highlighting the lack of investments from our allies isn’t provocative, it allows us to fight for the American taxpayers who have been footing the bill for far too long,” he added.

By picking Rubio and Waltz, Trump would also bring into his administration two key officials who have espoused a dim view of U.S. support for the more than 2½-year-old war in Ukraine — another stance unlikely to go over well in Tokyo.

Japanese officials have repeatedly warned that “today's Ukraine could be tomorrow's East Asia” — remarks widely seen as hinting at the possibility of a Chinese invasion of Taiwan.

Tokyo has emphasized the need to support fellow democracies and uphold international law. Senior government officials have also said that an invasion of Taiwan would represent an existential crisis for Japan.