The DA has welcomed President Cyril Ramaphosa's announcement of a nationwide lockdown, saying Covid-19 is "the biggest threat our country has faced in its 26 years of democracy".On Monday, Ramaphosa announced additional, stricter measures to combat the virus, including a national lockdown.With 402 positive cases confirmed by Health Minister Zweli Mkhize on Monday, DA leader John Steenhuisen said the lockdown was critical to contain the virus and prevent its spread.He added the virus would put pressure on our health and economic system, making the lockdown the right thing to do."Locking down our country and deploying the SANDF is something no South African would ever want to see in peacetime, but given the severity of our challenge, it is absolutely the right thing to do."The threat of this virus is akin to a wartime situation, and this requires of each of us to make sacrifices in our daily lives, and to some of the liberties of our democratic society," Steenhuisen said.He added these "drastic measure" could save lives."Three weeks of drastic measures now can save us many lives and buy us critical time for our healthcare professionals to deal with the unfolding crisis. If we don't make this sacrifice now, we will pay a far greater price in the long run."READ IN FULL | 'God bless South Africa': Ramaphosa announces 21-day lockdown, outlines range of dramatic interventionsThe lockdown is scheduled to last 21 days starting on Thursday and imposes serious restrictions on, among others, ordinary South Africans, travellers and businesses."It will test our healthcare system and it will test our ability to withstand an economic onslaught like nothing before. But above all, it will test the resolve of our people, and this is where we can take great strength," Steenhuisen said.He offered his and his party's assistance to Ramaphosa, as well as proposals on an economic recovery package."To the people of South Africa, I ask that you focus on what needs to be done and comply with everything that is required of you. Our efforts to beat this virus are only as strong as the weakest link in the chain. Everyone has to be 100% on board and committed," Steenhuisen added.