The first day of Liverpool's mass testing pilot ran "very smoothly," for the most part, said Matt Ashton, director of public health for Liverpool city council.
"It was good, it wasn't perfect, but we'll improve it," he told BBC Radio 4's Today programme on Saturday.
The city in the north of England is aiming to test up to 50,000 people a day once fully operational.
There were some hiccups with the operation however, as some people claimed they were made to line up for tests alongside people they didn't know had symptoms of the virus.
The UK government hopes to test the entire population of the city -- nearly 500,000 people -- in 10 days.
Liverpool has some of the highest infection rates in Britain. Weekly cases currently stand at 410.4 per 100,000, as of October 25, according to government data.
Liverpool soccer star Trent Alexander-Arnold sent a message to the people of his native city on Friday.
"Let's start the fightback against Covid, let's get tested," he said in a video posted on the club's official Twitter account.