Travellers returning to the UK from "red list" countries will be sent to quarantine hotels for 10 days, Boris Johnson has announced.
People will also be required to fill in a form explaining why their trip is necessary, with enforcement of the ban on leisure travel stepped up at airports.
The Prime Minister told the Commons that passengers will be "met at the airport and transported directly into quarantine".
The rules will apply to people arriving from countries where non-UK residents are already banned from entering the UK.
These 30 destinations cover all of South America, southern Africa and Portugal.
The cost of staying in one of these hotels has not been disclosed, but further details will be released next week.
Setting out more details of the measures, Home Secretary Priti Patel said: "Despite the stay-at-home regulations we are still seeing people not complying with these rules.
"The rules are clear, people should be staying at home unless they have a valid reason to leave.
"Going on holiday is not a valid reason, so we will introduce a new requirement so that people wishing to travel must first make a declaration as to why they need to travel.
"This reason for travel will be checked by carriers prior to departure."
Full list of countries included in 'quarantine hotels' policy
- Angola
- Argentina
- Bolivia
- Botswana
- Brazil
- Cape Verde
- Chile
- Colombia
- Democratic Republic of Congo
- Ecuador
- Eswatini
- French Guiana
- Guyana
- Lesotho
- Malawi
- Mauritius
- Mozambique
- Namibia
- Panama
- Paraguay
- Peru
- Portugal (including Madeira and the Azores)
- Seychelles
- South Africa
- Suriname
- Tanzania
- Uruguay
- Venezuela
- Zambia
- Zimbabwe
