The November elections are for local councils but are set to become a proxy vote on the government's handling of the months-long protests and Beijing's encroaching influence in the territory.
At least 750 children have been arrested by Hong Kong police since mass anti-government protests broke out in June.
Hong Kong Chief Executive Carrie Lam pulled out of the meeting when she discovered that Ted Cruz had told reporters about the plans.
The Hong Kong chief executive bowed to months of pressure and withdrew the controversial bill on Wednesday.
A Chinese official blamed the protesters for undermining Hong Kong's stability and prosperity through weeks of continuous demonstrations.
Trump has been reticent to criticize Beijing despite strong condemnations from the State Department and lawmakers from both parties.
"The way forward is genuine democratic elections, not violence in the streets," Taiwanese Foreign Minister Joseph Wu said.
At least 45 people were injured, one critically, after dozens of alleged triad gang members stormed a subway station and began attacking commuters.
In the run-up to Carrie Lam's victory, student leaders eschewed public protests and opted instead to use social media, leaflets and street booths to present their case that the election was undemocratic.
Public opinion polls show Carrie Lam's rival, John Tsang, as more popular with residents.
"It's not easy to be an activist facing the largest authoritarian regime in the world," says Demosisto campaigner Derek Lam.