US President Donald Trump's nominee to head the UN migration agency acknowledges a controversy over his social media posts on topics like climate change and Muslims, but insists that "retweets are not endorsements" and says he wants to be judged on his actions as a humanitarian.
Ken Isaacs spoke with reporters on Monday as the 169 member states of the International Organisation for Migration prepare to elect a successor to longtime diplomat William Lacy Swing as director-general in June.

