U.S. Sen. Jon Ossoff has not let up the pressure on the U.S. Postal Service’s significant mail delays in Georgia.

Ossoff on Monday said the mail issues were caused by a “complete execution debacle” of changes to mail processing that has seriously impacted people and businesses. He has led the charge questioning U.S. Postmaster General Louis DeJoy’s management.

“It was not thought through carefully; it was not planned well; there was nobody in charge,” Ossoff said while addressing elected officials and business leaders in Cobb County. “What I have done is put him under relentless, unsparing, civil, public pressure to do his one job.”

Earlier this year, significant delays in mail delivery in metro Atlanta led senators to mount pressure on DeJoy over his decision to open regional mail processing facilities. The Atlanta Regional Processing and Distribution Center in Palmetto opened in February and “led to a significant drop in performance,” DeJoy said in a letter to Ossoff.

After political pressure, DeJoy paused the rollout of mail processing changes, and mail delivery has slightly improved, Ossoff said.

Still, he said he wants to see “sustained improvement in on-time delivery data,” and his team is evaluating the Postal Service’s data to ensure it’s an accurate representation of mail delivery.

“I’m still hearing from constituents who are struggling with packages and letters,” Ossoff said after Monday’s event. “I think that this relentless public pressure has had an effect, and a positive effect, but I’m not going to let up until we see that the issues are truly resolved.”

At the event sponsored by the Cobb County Chamber of Commerce, Ossoff touted his legislative successes with infrastructure and workforce development investments in Cobb County and Georgia.

Cobb County has received $108 million in supplemental funding for infrastructure projects, Ossoff said, and federal funds also helped pay for a new workforce development center in Mableton that will provide training, resources and services for job seekers and businesses.

He’ll be in Georgia later this week as well, he said, visiting Air Force bases throughout the state, which he said has “some of the most important Department of Defense installations in the country.”

“A lot of what we’re trying to do is position Georgia to be strong, even as (the Department of Defense) transitions from legacy systems to new systems,” Ossoff said.