Speaking on Sky News’ Sophy Ridge programme, the Foreign Secretary said that the UK “is making steady progress” but is in “a sensitive moment.”
But he added: “We can’t just stay in lockdown forever. We have got to transition.”
He also said, if there an “uptick” in cases, “we will have to take further measures again and target the virus wherever it may appear”.
All non-essential shops will be able to open their doors again from June 15.
But some experts have warned that the UK may be easing lockdown too soon.
New case levels still high at around 8,000 per day and the track and trace system is not expected to be fully ready until the end of June.
Professor Devi Sridhar told Sky: “If your objective is to contain the virus, to drive numbers down and to try to in a sense get rid of it so no-one is exposed to it, then it is not the right measure right now to open up.
“It’s a big risk and gamble for exiting lockdown with a larger number of deaths than we did when we actually entered lockdown months back.”
Professor John Edmunds of the London School of Hygiene and Tropical Medicine, who is advising the Government on its coronavirus response, also questioned the move to lift lockdown.
Describing the rate of new coronavirus cases, he told the Guardian: “If you look at it internationally, it’s a very high level of incidence.”
“The issue is, clearly there’s a need to try and get the economy restarted and people back to their jobs and so on, and also there’s a social and a mental health need to allow people to meet with their friends and families.”
“I think many of us would prefer to see the incidence driven down to lower levels because that then means that we have fewer cases occurring before we relax the measures.
“I think at the moment, with relatively high incidence and relaxing the measures and also with an untested track and trace system, I think we are taking some risk here.”
Mr Raab said that the lockdown would continue to be eased gradually and remain under constant monitoring.
Referring to the deputy chief medical officer, he told Sky: “As Jonathan Van-Tam… has said, with a precarious moment we can ease up, we can protect life, but also livelihoods, get life back to something resembling normal, but we must monitor it very carefully.
“If there is any up-tick in the number of cases, if we stop making the progress I described, we will have to take further measures again and target the virus wherever it may appear.”
The foreign secretary’s comments come after a week of political criticism of the Government, with adviser Dominic Cummings keeping his job despite breaking lockdown rules.
And Mr Raab said on Sunday that he wasn’t aware of where the senior adviser was at the time, despite being the de-facto Prime Minister, with Boris Johnson ill with coronavirus.
He told Sky: “I just knew that he was out of action because he had come down with coronavirus and, given the situation we were in with the Prime Minister taken ill, and very seriously ill as it later emerged, I was just focused with the Government and with a great Cabinet team on making sure we continued to focus relentlessly on dealing with the virus.
“I mean I knew Dom was unwell and he was out of action, and obviously I wanted him and the Prime Minister to get well soon, but I wasn’t focused on his movements at all and I wasn’t aware of them.”