Ms James added the South East Wales Transport Commission was "very well advanced" in looking at alternatives to the relief road, which she described as "a very ecologically damaging set of concrete across protected Gwent levels."
"These things are never straightforward, and there is a range of opinions on all sides," said Ms James. "I'm very aware that some people in Newport want to build the M4, but I'm also very aware that a lot of people don't want to build the M4 and wish to protect the natural environment. That's why the commission was put in place.
"It's not just the people who live in Newport county, but all the people who live around it, and, indeed, further on in Wales, that are impacted by that, hence the need for the strategic approach to it."