It is getting harder to get a coronavirus vaccine, and Mayor Bill de Blasio says it may only get worse in the next couple of days if the city does not get a new supply immediately.

De Blasio says every second counts as some vaccination sites have already shut down across the city.

De Blasio blames it all on a limited supply from the federal government, but many hope that will quickly change as President Joe Biden unveils his national strategy.

Biden says the nearly 200-page response plan is based on science and not politics, truth and not denial.

Through executive action, Biden says immediate steps will be taken to create a partnership between FEMA, governors and mayors to create a COVID-19 response liaison, and have a point person at the federal level to maximize communication. The strategy is something that could help ramp up the supply in New York.

Meanwhile, thousands of appointments for the first dose were canceled or rescheduled this week, some of those appointments were for senior citizens, according to de Blasio.

The NYPD put out a memo that they're all out of the first dose vaccine because of the shortage, but said this shouldn't affect the second dose for officers who already got that first dose.

And now there's concern this could jeopardize the possibility of returning to in-person learning at schools. UFT President Michael Mulgrew reportedly said supplies to get educators vaccinated are dangerously close to running out.

De Blasio sounded the alarm, pleading for help.

"New York City is going to run through everything we have in a matter of days. We need resupply. That's the clearest statement it could be to the state, to the federal government, to the manufacturers, get the vaccine where it can be put into arms urgently. That's what we're doing," de Blasio said.

He says they are hoping the Biden administration will ramp up production.