Ms Truss said she understood the “importance and sensitivity” of the location.
Serbia and Kosovo opened a break with the European Union in 2020 by deciding to set up embassies in Jerusalem.
Ms. Truss meets world leaders for the first time at the summit in the US.
On Wednesday, she held talks with US President Joe Biden, who told her, “You are our closest ally in the world.”
A spokesman for the prime minister said the couple agreed to end Russia’s energy dependency and support Kiev.
“Leaders condemned Putin’s recent belligerent statements about Ukraine,” he said. They agreed that his actions emphasize the need for allies to continue their economic and military support for Ukraine.