WASHINGTON (NEXSTAR) — The urge for holiday travel and the nationwide surge in COVID-19 cases have combined to increase the demand for testing.

COVID-19 testing sites across the country have been overwhelmed ahead of Thanksgiving, and Sen. Ben Cardin, D-Maryland, said it’s a cause for concern.

“We need a greater capacity for testing and that request was never heeded,” Cardin said.

Cardin said the House-passed HEROES Act would have helped handle the onslaught by providing millions more dollars for testing, but the bill remains stalled in the Senate.

“We’d like to be able to have testing on-demand but we just don’t have the capacity right now because we weren’t as prepared as we should’ve been,” Cardin said.

Quest Diagnostics, a clinical laboratory company, said in a statement that “the laboratory industry as a whole is experiencing increasing constraints on supplies, including test kits.”

The company also said the demand for tests has increased nearly 50% since the end of September.

Dr. Gary Procop with The Cleveland Clinic said the current testing strategy, which is on a state-by-state basis, isn’t working.

“From the very beginning we have called for a national testing strategy,” he said. “There are best practices, so let’s get the experts to tell us what the best practices are with regard to testing and then follow those.”

Cardin said while there is a light at the end of the tunnel with news of a promising coronavirus vaccine, Congress still needs to work to pass additional COVID relief for Americans.