In a written statement, Knoblach called the allegations false and "indescribably hurtful."
A Queens woman has been charged with stabbing five people, including three baby girls, at a maternity center in the borough early Friday.
Britain is among the least religious countries in the world. But it is experiencing a boom in the number of new Catholic nuns.
The issue has for decades caused tensions between the Holy See and Beijing.
Foreign Minister Javad Zarif immediately blamed the attack on regional countries and their "U.S. masters."