After former President Donald Trump announced his position that abortion rights should be decided by individual states, the leading anti-abortion group supporting Republican candidates said his stance fell short.

In a statement Monday morning, Susan B. Anthony Pro-Life America’s president, Marjorie Dannenfelser, said she was “deeply disappointed” in Mr. Trump’s refusal to endorse a federal ban on abortion, adding that allowing states to decide “cedes the national debate to the Democrats who are working relentlessly to enact legislation mandating abortion throughout all nine months of pregnancy.”

“If successful, they will wipe out states’ rights,” she added.

Still, Ms. Dannenfelser said that the group and its grass-roots members will work “tirelessly” to defeat President Biden and Democrats in November.

Antiabortion groups like Susan B. Anthony Pro-Life America have long endorsed a federal ban on abortion and have pushed conservative lawmakers to do the same. Allowing the states to decide their own abortion measures, they argue, would make the procedure available in some states led by Democrats and lawmakers who support abortion access.

Some conservative groups, however, were not entirely dismayed by Mr. Trump’s stance.

Kristan Hawkins, the president of Students for Life Action, a group that trains and supports young anti-abortion organizers, called the former president’s statement “a step in the right direction,” and said she was encouraged by his refusal to call for “a divisive late-term limit.” She maintained that the group still supports a federal ban and added, “your state lines should never mean the beginning or end of your human rights.”