Those who work with him say Tillerson is unflappable and steely-focused on making concrete arguments with the leaders he meets despite the sound and fury in Washington. Still, some foreign leaders and diplomats are left wondering whose voice speaks loudest, whom to believe, who is in charge when the White House and its chief diplomat espouse different views.
Confusing issues further, the State Department has reeled in or corrected several hawkish statements by the U.S. ambassador to the United Nations, Nikki Haley, who is said to be close to Trump and at odds with Tillerson.
The contrasts sometimes play out in real time. In Mexico City last week, Tillerson held a news conference with Mexican Foreign Minister Luis Videgaray and stuck to pro forma comments praising friendship between the two countries. "We still value immigrants," Tillerson said.
At nearly the same time, Trump met with Homeland Security officials in Sterling, Va., reiterated his plans to build a wall along the U.S. border with Mexico, an idea Mexico has roundly rejected, and threatened to cut off aid to unnamed Latin countries that don't do enough to support U.S. policies.
A senior official on the Tillerson trip called Trump's comments "unhelpful," unusually frank criticism from a diplomat.
In Peru and in Colombia, Tillerson sought regional support for stiffer economic sanctions against the socialist government in Venezuela -- but was grilled by local reporters and officials about why his comments differed from those emanating from the White House.
In Kingston, Jamaica, a reporter for state television pressed Tillerson to explain Trump's reported description of largely nonwhite countries as "shitholes."
"How should we perceive your visit today," asked the reporter, Andrea Chisholm, "and how can Caribbean countries think that you respect us, and it's not more of the United States just throwing their power around?"
Tillerson responded that he was there "to reinforce the partnership" with Jamaica and the Caribbean region.
An American reporter later asked if Tillerson was frustrated at being repeatedly pushed off message by the president.