The cabinet of United States President Donald Trump has started to take shape, with its first nominee confirmed to a role: Florida lawmaker Marco Rubio.

On Tuesday, Rubio, 53, was sworn in as secretary of state, the country’s chief diplomat and the highest-ranking role in the cabinet, second only to the vice president and president.

The ceremony came after a rare unanimous vote in the Senate to elevate him to the role.

All 99 members voted in favour: The only vote missing in the 100-seat chamber was Rubio himself, as he had to step down as senator to take up his new position.

Speaking at the swearing-in ceremony, Vice President JD Vance described Rubio as a “needed departure from a generation of failed foreign policy”.

“He is a bipartisan solutions-seeker, a guy who can actually get things done, but a conservative of great principle and vision,” Vance said. “And I think more than anybody that I’ve met in Washington over the last few years, Senator Rubio, I think, understands the distinctive priorities of President Trump.”

But what has Rubio pledged to do in his new role? And what did Tuesday’s ceremony reveal about the newly-minted diplomat? Here are three takeaways.

Rubio defends State Department employees

In his first remarks as secretary of state, Rubio praised the federal employees who conduct day-to-day operations at the US Department of State, the executive agency he is now charged with running.

“This is an extraordinary honour and a privilege to serve in this role, to be here — frankly, to oversee the greatest, the most effective, the most talented, the most experienced diplomatic corps in the history of the world,” Rubio said.

“ I want to also thank the locally employed staff, the nationals of those countries who work with us,” he added. “Without their help, without their support, it would be impossible for us to conduct our mission.”

Rubio’s remarks come at a sensitive time for federal civil servants, as Trump sweeps into office with a raft of executive actions designed to rein in government bureaucracy.

Just one day earlier, on the first day of his second term, Trump threatened to fire those employees he perceives as loyal to his predecessor, Democrat Joe Biden.

“To gain immediate control of the vast federal out-of-control bureaucracy, I will implement an immediate regulation freeze, which will stop Biden bureaucrats from continuing to regulate,” Trump told supporters gathered at the Capitol One Arena in Washington, DC.

“Most of those bureaucrats are being fired. They’re gone. Should be all of them, but some sneak through.”

By contrast, Rubio entered his new role defending the work of the State Department and praising its employees.

“ There’s no other agency in the world, there’s no other agency in our government, that I’d rather lead because of the talent that’s collected here in this room and those watching around the world,” he said.

Rubio pledges to advance ‘America First’

Still, Rubio once again restated his firm commitment to advancing Trump’s “America First” policy platform, and warned that changes would come to the State Department as a result.

“There will be changes, but the changes are not meant to be destructive. They’re not meant to be punitive,” he told the audience at his swearing-in, made up largely of State Department employees.

Rubio outlined a vision where the State Department takes more of a leading role in government affairs.

“Sometimes, the Department of State has been sort of relegated to a secondary role because some other agency can move faster or seems to be bolder or more creative,” Rubio said.

“It’s not your fault. But we’re going to change that. We want to be at the centrepiece. We want to be at the core of how we formulate foreign policy.”

The former senator explained that the department’s role moving forward would be more inward-looking, seeking to craft policies that would make the US “stronger or safer or more prosperous”.

He also advised employees to look at Trump’s election to a second term in November as a mandate to centre US priorities.

“Our job, across the world, is to ensure that we have a foreign policy that advances the national interest of the United States,” he said, adding: “I expect every nation on earth to advance their national interests.”

Balancing hawkishness with peace

But despite his unifying tone on Tuesday, Rubio faced protesters as he sat for Senate hearings about his nomination over the past week.

“Little Marco, keep your hands off our country!” one protester shouted, denouncing the US’s involvement in “forever wars”.

Another, speaking Spanish, criticised hardline US policies abroad: “The sanctions of Marco Rubio are killing kids in Nicaragua, Cuba and Venezuela.”

Rubio brushed aside the interruptions with light-hearted remarks. “I get the bilingual protesters,” the lawmaker, a child of Cuban immigrants, quipped. He will be the first Latino person to serve as secretary of state.

But the protests were a reminder of Rubio’s reputation as a foreign-policy hawk, known for his aggressive stance to US adversaries overseas.

One particular target during Rubio’s confirmation hearings was China, which has sanctioned the Florida politician for his support of Hong Kong’s autonomy. He told senators last week that he believed the US-China rivalry would “define the 21st century”.

“The Communist Party of China that leads the PRC [People’s Republic of China] is the most potent and dangerous near-peer adversary this nation has ever confronted,” Rubio said.

He explained the threat of China dwarfed that of the US’s Cold War rival, the Soviet Union.

“They have elements that the Soviet Union never possessed. They are our technological adversary and competitor, an industrial competitor, an economic competitor, a geopolitical competitor, a scientific competitor now — in every realm.”

Still, despite his hawkish posture, Rubio told State Department employees on Tuesday that he planned to follow through with Trump’s promises of delivering world peace.

“That’s what we endeavour to do: to promote peace around the world because that’s in our national interest,” Rubio said. “Without peace, it is hard to be a strong nation, a prosperous nation.”

He did, however, admit that “there will be conflict”. In explaining how he viewed US policy abroad, he echoed rhetoric popular among the Christian right: namely, that the US is founded on a religious mandate.

“We are, at the end of the day, a nation founded on a powerful principle. And that powerful principle is that all men are created equal because our rights come from God, our creator — not from our laws, not from our governments,” Rubio said.

“We hope the entire world can one day live under that. And we will always, always be strong defenders of that principle.”