Sadiq Khan thanked St Albans Congregational Church in Queens for its warm welcome.
Wonderful warmth, friendship & hospitality from the congregation at St. Alban's Church in Queens, NYC this morning. pic.twitter.com/Y48CAS3OsR
— Sadiq Khan (@SadiqKhan) September 18, 2016
Mr Khan has also met the New York Mayor Bill de Blasio, spoken to tenants about his plans for a London Living Rent and visited a major synagogue.
The mayor's visit coincided with a bomb blast in New York in the Chelsea area of Manhattan on Saturday night, which injured 29 people.
He's said his thoughts and prayers are with all those affected.
New York police are currently questioning five people in relation to the incident; no arrests have been made yet.
In New Jersey on Sunday, a backpack with five suspicious devices was found near a train station. One of them exploded when a controlled detonation was carried out.
A bomb also exploded at a charity race on Sunday morning, though no one was injured.