Secretary of State Rex Tillerson speaks to employees at the State Department on Feb. 2. (Mandel Ngan/AFP/Getty Images)

Secretary of State Rex Tillerson assured career diplomats Thursday that he values and will support their work, as he began his first day running a department in turmoil over the policies of the new Trump administration.

Tillerson told hundreds of employees gathered in the State Department’s lobby that among the core principles with which he will run the department are respect and honesty, even over points of disagreement. It was a thinly veiled reference to a dissent memo that has been signed by unprecedented numbers of diplomats and other employees objecting to President Trump’s order suspending travel to the United States for citizens of seven predominantly Muslim nations and ceasing refugee admissions for the time being.

Tillerson said he appreciates dissenting views.

“Honesty will undergird our foreign policy,” he said. “We’ll start by making it the basis with which we interact with each other.”

Then he addressed the lingering concerns head-on, suggesting they have no reason to fear retaliation for expressing alternative viewpoints.

“No one will tolerate disrespect of anyone,” he said. “Before we are employees of the State Department, we are human beings first. Let us extend respect to one another, especially when we may disagree.”

As Tillerson entered the building’s lobby shortly after 10 a.m., holding hands with his wife, Renda, he was greeted by applause from hundreds of employees who had been waiting as long as 90 minutes. The traditional welcoming was polite, but the applause was not as loud, sustained or filled with gleeful hoots as it was when former secretaries John F. Kerry and Hillary Clinton first arrived.

The warmest applause came when Tillerson thanked Thomas Shannon, the No. 3 official in the department, who had been serving as acting secretary of state until Tillerson was confirmed.

When Tillerson joked, “Hi, I’m the new guy,” he was met with laughter and clapping.

He made almost no mention of foreign affairs, and focused his remarks on letting the employees know he cares about their work and their safety.

“You are our emissaries of our nation and the ideals we stand for,” Tillerson said. “When people see you, they see America.”

But Tillerson also delivered some subtle warnings that he may make changes at the department, and that he expects employees to get behind the new administration.

“I know this was a hotly contested election, and we do not all feel the same way about the outcome,” he said. “Each of us is entitled to the expression of our political beliefs. But we cannot let our personal convictions overwhelm our ability to work well, as one team.”

In addition to the dissent memo, a few career Foreign Service officers have resigned in protest of the new administration, and others have expressed doubts about whether Trump understands or values the traditional work of diplomacy.

Tillerson signaled Thursday that he grasped the risks diplomats often face. In an apparent reference to the 2012 attack at the U.S. mission in Benghazi, Libya, in which Ambassador J. Christopher Stevens and three other Americans were killed, he made an expansive list of those he considers State Department family. Among them were Foreign Service officers, civil servants, locally hired staff, third-country nationals, interns and contractors.

“When I wake up each morning, the very first thing I ask myself is, are all of our people safe?” he said.

Driving the point home, he walked down some steps after finishing his speech and paused to pay his respects at a wall displaying memorial plaques to State Department employees who died while on duty. And he pledged that over the coming days he would make the rounds of the building, aiming to shake hands with everyone.

In his first full day on the job, Tillerson spoke by phone with the foreign ministers of Canada and Mexico, and met with the foreign minister of Germany.

Tillerson takes office just as tensions with Iran are rising over its latest ballistic missile test. On Wednesday, just before Tillerson was being confirmed in the Senate, national security adviser ­Michael Flynn appeared at the White House press briefing to announce that Iran was being “put on notice” over what he called its “provocative” breach of a U.N. Security Council resolution.

Iranian officials brushed off the remarks by what they called the “inexperienced” Trump administration, and vowed to continue testing missiles. Trump and his advisers have said they will take a more aggressive stance with Iran, particularly on U.N. sanctions related to missile tests like the one Tehran conducted last weekend in an apparent measure of the fledgling administration. With Tillerson in place now, it remains to be seen how much of an impact he will have in defusing the tensions or guiding the confrontation.

In addition, Tillerson has dozens of positions that must be filled with nominees who require Senate confirmation.

Tillerson is the only person in the State Department who has been nominated and confirmed so far. Two deputies, six undersecretaries and 21 assistant secretaries all require Senate approval. The handful of career diplomats who are staying on at least temporarily in the same jobs they held in the Obama administration stood behind Tillerson as he spoke Thursday. The majority of the senior jobs at the State Department are being done by temporary, acting substitutes who were deputies under their previous bosses.