At a White House news conference, he described Powell as a "consensus builder for sound monetary policy" and said he understands what it takes to make the economy grow.
As it happened, while sterling fell sharply against the dollar following the UK's interest rate decision, the markets barely moved when the appointment was confirmed. That was probably because Powell's nomination was leaked 24-hours earlier.
The move marks a break with recent tradition as Ms Yellen's three immediate predecessors were all reappointed for a second four year term by presidents from the opposite party to the one that put them in office.
SKY News.
