WASHINGTON, Feb 15 (Reuters) - Rex Tillerson left on his maiden foreign trip as U.S. secretary of state on Wednesday, heading to Bonn to interact with counterparts from the G20 top economies at a time many are wondering how far President Donald Trump's "America First" message will reshape U.S. foreign policy.
From North Korean provocations to fresh reports that Russia has deployed a new cruise missile, concerns about China's aggressions in the South China Sea, and conflicts in Yemen, Syria and Ukraine, there is no shortage of global challenges.
But senior U.S. officials cast Tillerson's two-day trip as a "listening tour," conceding that this may frustrate some of his counterparts.
Tillerson will also participate in a series of sessions on a shifting global order, cooperation with Africa and conflict prevention. It will be a prelude to the G20 leaders summit in Hamburg, Germany in July, which Trump is due to attend.
Allies worry about Trump's unpredictability and how far he will go in warning China and Iran about their behavior, whether he will back out of long-standing treaties, tear up the nuclear agreement with Iran, build a border wall with Mexico or cozy up to Moscow.
Tillerson heads to the meetings following the resignation of national security adviser Michael Flynn for misleading the White House about his contacts with Russia's ambassador to the United States. Flynn had been the new administration's main contact for many foreign ambassadors to the United States.
"I think he is mostly going on a listening tour," said a U.S. official who spoke on condition of anonymity, saying that may disappoint U.S. allies. "If our (guy) says, 'well, I am just here to listen,' that's going to be dispiriting."
Tillerson, the former Exxon Mobil CEO, has international business experience but none in government. State Department officials said he will meet with counterparts from Britain, Saudi Arabia and Oman while in Bonn, and participate in larger meetings on Yemen and Syria.
He also will hold his first meeting as secretary of state with Russian Foreign Minister Sergei Lavrov, who met regularly with John Kerry on a ceasefire to end Syria's conflict.
The G20 is made up of developed economies and emerging nations such as China, India, Indonesia, Mexico, South Africa and Brazil.
Jim Wilkinson, a senior adviser to former Secretary of State Condoleezza Rice, said it was vital for Tillerson to establish a relationship with fellow ministers during his first trip.
"That chemistry with counterparts begins on the first trip," he said. "Secretary Tillerson and his counterparts will be working on some of the toughest issues around the world and that's going to require trust."
While Tillerson has been on the job for just two weeks and may not be immersed in all subjects yet, Wilkinson said: "Foreign ministers will be understanding that in the early days he may not have all the answers, but they will want to know they have a conduit to someone who can speak for the U.S." (Additional reporting by Arshad Mohammed; Editing by Warren Strobel and David Gregorio)