Switzerland announced Thursday that it had clinched a deal with the United Kingdom that allows the existing rights of Swiss and British nationals already residing in each other's countries when Britain leaves the European Union (EU).

"The rights granted in this agreement apply indefinitely," said the Federal Council, the Swiss cabinet, in a statement, noting that around 77,500 Swiss and British citizens live in each other's countries.

The affected citizens of each country will be able to continue working as foreign nationals and provide the same services. The deal also guarantees the same social security provisions and mutual recognition of professional qualifications.

"However, the terms of the agreement do not apply for the UK and Swiss citizens who move to the respective foreign country after the (EU free movement of persons' protocol) ceases to apply," the statement said.

The Swiss government said that at the end of 2017, some 43,000 British citizens were living in Switzerland, and about 34,500 Swiss citizens were resident in the United Kingdom.

Should Britain exit the EU without concluding a deal on March 29, the newly agreed provisions would take immediate effect said the Swiss government.

If Britain and the EU can agree their separation terms, the provisions announced Thursday would come into effect following the agreed transition period.

The same will apply to a trade accord, which, the Swiss government said days earlier, had been approved with Britain. It aims to maintain existing economic and trade relations with the United Kingdom after it leaves the EU under what is known as Brexit.

In 2017, the UK was Switzerland's sixth largest export market valued at 11.4 billion Swiss francs (11.44 billion U.S. dollars), and its eighth largest supplier with imports of 6.1 billion Swiss francs.