Drug therapy that appears to shorten recovery time for people with coronavirus is available on the NHS.
Remdesivir is an antiviral medication that was originally developed to fight Ebola.
UK regulators say there is enough evidence to endorse its use in some hospital patients.
At the moment and due to a limited supply, it will go to those who are most likely to benefit.
The United States and Japan have already made similar arrangements to provide rapid access to the drug before entering into a marketing agreement.
The drug is currently undergoing clinical trials worldwide, including in the United Kingdom. Initial data suggests that it can reduce recovery time by about four days.
It is not known how much pharmaceutical stock Gilead Sciences has available to treat British patients.
The allocation of the drug will be based on the advice of doctors.
Innovation Minister Lord Bethell said: “This shows fantastic progress. As we go through this unprecedented period, we must be at the forefront of the latest medical advances, while ensuring that patient safety remains a top priority.
“The latest expert scientific advice is at the heart of every decision we make and we will continue to monitor the success of remdesivir in clinical trials across the country to ensure the best results for UK patients.”