US secretary of state Rex Tillerson is preparing to start today a diplomatic mission to Europe, days after reports surfaced of a White House plan to force him out.

Tillerson is scheduled to attend NATO, EU, and OSCE meetings and to hold bilateral talks with Belgian and Austrian officials in Brussels and Vienna on December 5-7. He is also due to make a stop in Paris on December 8 for meetings with French officials.

An encounter with Russian Foreign Minister Sergei Lavrov is also planned on the sidelines of a meeting of the Organization for Security and Cooperation in Europe (OSCE) in the Austrian capital.

Tillerson on Saturday denied that he was leaving his post to be replaced by CIA Director Mike Pompeo. Senior administration officials on said President Donald Trump was mulling a plan to oust the top U.S. diplomat, whose relationship with the president has been strained by Tillerson’s softer line on North Korea and other policy differences.

Ahead of his European tour, Tillerson stressed Washington’s commitment to European security, especially as Russia continues what he called its “aggressive behaviour.” Tillerson said Russia’s military interventions in Georgia and Ukraine, and interference in European elections and politics were unacceptable.

The president and the secretary of state have often contradicted each other in public statements regarding major international issues.

In Brussels, Tillerson will participate in a December 5-6 NATO Foreign Ministers Meeting and will also meet with EU foreign policy chief Federica Mogherini and foreign ministers of the bloc to discuss “U.S.-EU cooperation on major global issues,” the State Department said in a statement.

On December 7 in Vienna, he will attend the opening and first plenary sessions of the OSCE Ministerial Council — the central decision-making and governing body of the organisation.