The British Home Office received more than five million applications from EU citizens wishing to remain in the UK post-Brexit.
EU citizens eligible to stay after the Brexit transition period have until June 30 to apply.
Interior minister Priti Patel said: "It is fantastic news that over five million applications have been made to the hugely successful EU Settlement Scheme.
"It’s the biggest scheme of its kind in UK history and will mean European citizens and their families can continue to call the UK home."
So far, more than 4.5 million grants of status have been made.
The government had pledged to secure the rights of millions of Europeans in UK law after its departure from the EU.
However, some groups are saying that because of the pandemic there is a risk some people could "slip through the net" and face being deported.
Covid-19 makes it more difficult for people to access help with their applications, ministers said.
The Welsh government's external affairs committee wrote to Welsh and UK ministers outlining its concerns.
"EU citizens have an important role to play in Wales," committee chairman David Rees told the BBC.
"Under the Brexit agreement they have the right to stay in the UK. This committee is concerned that the excellent support that was available pre-pandemic is dwindling and that people are at risk of slipping through the net."
The UK government invested an initial £17 million ($23.7 million) into 72 organisations across the country to help the vulnerable and those hard to reach to apply to the scheme.
This month it announced an additional £4.5 million in funding for the networks.
It is aimed at helping victims of human trafficking or domestic abuse, those with severe mental health conditions, those without a permanent address, and those who are elderly or isolated.
Minister for Future Borders and Immigration Kevin Foster is urging those who have not applied to submit their applications.
"It’s great news there have been more than five million applications to the EU Settlement Scheme ahead of the June 30 deadline," he said.
"My message to European citizens and their family members is simple – apply now and join the millions who have already been through the simple process to secure their status.
"There is plenty of support available and the new funding announced means no stone will be left unturned in ensuring everyone gets the help they need."
The Home Office also launched a new £1.5 million wave of UK advertising to ensure EU citizens and their family members are aware of the deadline and know they need to apply.
Citizens Advice Scotland helped more than 11,000 people, said its chief executive, Derek Mitchell.
"The Citizens Advice network in Scotland has played a vital role in providing free, impartial and confidential advice on the EU Settlement Scheme," he said.
"Our team of specialist advisers continue to provide support during the coronavirus pandemic through our national helpline and we are pleased to partner with the UK government in delivering this important service."
The Home Office has a team of more than 1,500 people working on the EU Settlement Scheme, with support available seven days a week.
All EU citizens who hold a valid passport and any non-EU citizen family members who hold a valid biometric residence card can apply for settled status.