Mr Hancock also said that Britain would trial a new antigen test - which shows whether people now have COVID-19, the disease caused by the new coronavirus - that would return results in 20 minutes without needing to be sent to a lab for processing.
Both tests are available at clinics in and around Monroe County and across upstate NY - but there are big differences not just in what they test for, but also in how to get them and how much they'll cost. But as insight improves with antibody tests, they tell us how our body reacts and how the virus spreads throughout country.
Mr Hancock said: 'I can announce today that we have signed contracts to supply, in the coming months, over 10 million tests from Roche and Abbott.
'Three further tests are being assessed right now, ' the health secretary added.
He said they would begin rolling out the tests in phases beginning next week, starting with health workers, and then patients.
He said: "The public need to be aware that those tests are not the same as those we have evaluated and approved for use".
Another use of such tests would be to better learn whether exposure to coronavirus and presence of antibodies gives people immunity from catching it again, and if so for how long.
Receiving results on site will mean people with symptoms will be given immediate certainty as to whether or not they have the virus.
Britain has been in talks with Swiss drugmaker Roche Holding AG to buy an accurate COVID-19 antibody test, following the lead of the European Union and United States which have already given preliminary approval to the tests.
The trials will take place in Accident and Emergency departments, GP testing hubs and care homes in a bid to speed up the lifting of lockdown restrictions.
Unlike other tests, the loop-mediated isothermal amplification (Lamp) swab test does not require a temperature change to identify the pathogen. Currently, he said, 90% of results come within 48 hours, and nearly half within 24 hours.
Matt Hancock told yesterday's briefing: 'We're developing this critical science to know the impact of a positive antibody test and to develop the systems of certification to ensure people who have positive antibodies can be given assurances of what they can safely do'.
A smartphone app is now being tested, while the government has also promised to recruit 25,000 tracing staff.
Newton reiterated this, saying the app was an "additional component" which could be "layered on top of the more personal contact tracing" by officials.