The radical Islamic State (IS) has reportedly claimed responsibility for the attack at Holey Artisan Bakery, in Gulshan diplomatic zone, which is frequented by foreigners.
The US assistant secretary of State stayed there for around 20 minutes amid police barricade surrounding the area on Monday.
Biswal is visiting Dhaka following the attack and has offered Washington’s support to build Bangladesh’s capabilities in countering terrorism.
Earlier, she met Foreign Minister AH Mahmood Ali, and Dhaka-based diplomats including the Indian High Commissioner, among others, to discuss security issues.
World leaders had earlier pledged to support Bangladesh in combating terrorism following the unprecedented attack.
Italy and Japan have decided to conduct coordinated diplomatic and intelligence operations in Bangladesh.