Salesforce Chief Executive Marc Benioff revealed on Tuesday that he has been at his most aggressive with President Donald Trump when advising him to implement apprenticeship schemes to help retrain swathes of U.S. workers.

Benioff first raised hopes of introducing an extensive apprenticeship program at a White House meeting in March. He emphasized that the U.S. had a great opportunity to create apprenticeships for its workers and suggested Trump should target a “moonshot goal” of 5 million new apprenticeships over the next five years. A “moonshot” in this context refers to the launch of a ground-breaking project without the expectation of profit in the near term.

“I went to President Trump and said we have to have an apprenticeship moonshot, we have to be ready to retrain people,” Benioff told CNBC on the sidelines of the World Economic Forum in Dalian, China.

Benioff stressed that because aggressive new technologies – such as artificial intelligence – were forthcoming, governments would need to implement policies now in order to ensure people could remain employable in the future.

“We need to look to countries like Germany and Switzerland who have amazing apprenticeship programs and do this incredible next generation workforce development and that’s really the advice that I have given most aggressively,” he said on Tuesday.

The March meeting between business leaders from German and U.S. companies in which Benioff first aired his views gained notoriety in the weeks that followed as a result of the somewhat awkward encounter between Trump and German Chancellor Angela Merkel.

Trump appeared to ignore requests for a handshake as the two premiers sat posing for the cameras in the Oval Office ahead of a joint press conference.

“I was in that meeting when Angela Merkel was at the White House with Donald Trump and I felt that the comments that were made by the media were actually quite overblown. I saw them getting along quite well together and I’m very optimistic about the continued (strong) relationship between both countries,” Benioff said.