WASHINGTON — Concerned governors on Thursday cautioned President Trump against reopening the economy too quickly, telling him they were still experiencing critical coronavirus test shortages, The Post has learned.

During a conference call where Trump presented his guidelines to reopen the economy, multiple state leaders told the president they were still struggling to secure enough complete testing kits and were worried about a second spike in infection.

“We have an enormous lack of manufacturing capability for testing kits themselves,” said Gov. Jay Inslee (D-Wash.), according to a person familiar with the call.

Describing it as a “hand-to-mouth existence,” Inslee said he had more than 160 nursing homes with COVID-19 cases that he could not test because the state lacked kits and swabs to get the samples needed for them.

“That is an extreme limitation, and we literally are unpacking bags from China by the minute and getting them to a nursing home,” he said.

Trump promised to ramp up manufacturing of these testing elements, saying 5.1 million more swabs would be delivered to states by the end of the month.

Rear Admiral John Polowczyk, the task force’s deputy director for operational logistics, also suggested Inslee use supplies more “judiciously.”

Kansas Gov. Laura Kelly, a Democrat, said she felt uncomfortable sending people back to work with long delays in testing results, while others raised the alarm over vaccines.

“I don’t think we can get back to normal unless you develop a vaccine,” Gov. Gary Herbert (R-Utah) told Trump, according to a person familiar with the call.

“You’ve got to wait and give people confidence to go out without infection. So, we need to have an all hands on deck approach,” he continued.

Trump promised the vaccine was “coming along really well” and said Johnson & Johnson and several other companies were “very far advanced” on the vaccine.

Most governors on the call, however, praised the president for his response, while Trump also repeatedly thanked state leaders for their hard work.