Bayer AG has pledged to add U.S. jobs and investment after meeting with President-elect Donald Trump, the latest in a string of public displays from companies looking to head off criticism from the incoming administration about job losses.

The German chemical conglomerate, which is seeking regulatory approval for its planned $57 billion purchase of biotech seed maker Monsanto Co., said Tuesday it would step up research investments and create “several thousand” new high-tech positions in the U.S. after completing the deal...