In 2018, Gabriel was among six of 11 candidates nominated by Siemens to join the board of directors of Siemens Alstom, a planned merger of two railway companies; he ended up not taking the office when the merger was prohibited by the European Commission amid competition concerns. Also in 2018, the German government's ethics committee rejected his request to join the supervisory board of Kulczyk Investments, citing potential conflict of interest. In 2019, he rejected an offer to become the head of the German Association of the Automotive Industry (VDA) after media reports that he was in line for the post caused a public outcry and prompted accusations of nepotism. More recently, he said Donald Trump is right to criticize China and to negotiate with North Korea.