President Joe Biden on Monday pledged to support governors struggling with the omicron variant of Covid-19,  but acknowledged the states will need to take the lead in controlling the pandemic.

Speaking just before a meeting with some of the nation’s governors, Biden said: “There is no federal solution. This gets solved at a state level.”

Those comments represent one of the most explicit acknowledgements to date from the Biden administration that it will need help from state and local governments in its efforts to curb the spread of Covid-19.

The president may be concerned that federal initiatives to contain the virus can’t be effective without states’ help. The comments could also be an attempt to put added pressure on governors to take a greater role in trying to control the disease.

After his remarks, Biden took one question about whether he supports revised recommendations for shortened quarantine periods.

“I rely on my medical team. I get a recommendation, I follow it,” he said. 

The Centers for Disease Control and Prevention recently edited its recommendations for people who may have been exposed to the virus. Instead of the standard 14-day quarantine it had recommended, the CDC says that suspected exposures should result in a quarantine of 10 or seven days based on test results and symptoms.

The omicron variant poses a multifaceted threat to Biden, who campaigned on the federal government’s ability to curb the pandemic. The president on Monday reiterated some of the promises he made last week, including the federal government’s purchase of 500 million rapid coronavirus tests.

“My message to the governors is simple: if you need something, say something,” he said. “We’re going to have your back any way we can.”

The administration plans to distribute the tests free to Americans, support more vaccination and testing sites, and deploy 1,000 military medical professionals to augment hospital staff nationwide.

But the virus’s ability to mutate, spread and occasionally lead to positive cases among those who have received a vaccine has made the administration’s promise to slow the disease more difficult. The virus and vaccine have become politicized. Many Americans, especially those supportive of former President Donald Trump, refuse to be vaccinated.

Reflecting differences in attitude toward the virus and public safety priorities nationwide, governors’ responses to the Biden administration’s efforts have been mixed.

Texas Gov. Greg Abbott, a Republican, issued an executive order in October prohibiting any entity, including private businesses, from imposing Covid-19 vaccination requirements on employees or customers. Gov. Ron DeSantis of Florida, thought to be a 2024 Republican presidential contender, has in recent months broken away from federal public health guidance and curtailed mask and vaccine mandates.

The Biden administration has for weeks stressed that Americans should take extra care during the 2021 holiday season to protect their families from the spread of the disease.

The president’s remarks came as Covid-19 cases surged over the Christmas holiday weekend.

The highly infectious omicron variant has in the past week caused a handful of states, including New Jersey and New York, to report more coronavirus cases than in any other seven-day period during the pandemic.

While early signs suggest the variant may cause more mild symptoms, health experts urge rigorous public safety protocols and say the variant’s rapid spread could strain the U.S. hospital system and lead to more deaths.

“Every day it goes up and up. The last weekly average was about 150,000 and it likely will go much higher,” U.S. infectious disease expert Dr. Anthony Fauci said Sunday on the ABC program “This Week.”

On Wednesday, before the holiday weekend disrupted Covid trackers, the seven-day national average of new daily cases surpassed 176,000, a 44% increase over the past 14 days. Deaths also rose during that time, to a seven-day average of 1,213 from 1,103.