Sen. Mark Kelly (D-Ariz.) announced Monday he tested positive for COVID-19, which is expected to sideline him from votes for at least several days.

“Unfortunately, after four years of avoiding it, I’ve got COVID-19. I’m feeling alright and look forward to returning to the Senate for votes as soon as I can,” he said on X, formerly Twitter.

The senator’s absence comes as the House and Senate continue tense negotiations on a border security and foreign aid deal.

Kelly’s bout with COVID-19 corresponds with a national uptick in the virus this month. Medical experts blamed holiday social gatherings and winter weather for the increase, as well as a new JN.1 omicron variant of the virus.

Rates of hospital admissions and hospitalizations have dipped from recent peaks earlier this month but still hold at rates higher than before the holidays, according to Centers for Disease Control and Prevention data. 

Deaths from COVID-19, however, have continued to increase. The death rate increased by about 10 percent in the most recent week data was available, with the highest rates of COVID-19 in the Midwest.