Spain announced on Friday that entry for passengers travelling from the UK by air and sea will be prohibited till January 19, according to the Official State Gazette.
Spanish nationals and those with legal residency in Spain, however, will be allowed entry.
Due to the "uncertainties... about the scope of the new SARS-CoV-2 variant, more information will be needed on the evolution of the epidemiological situation in the United Kingdom," the Gazette stated, Xinhua news agency reported.
The new coronavirus variant, first reported by the UK, is said to be up to 70 per cent more transmissible.
Starting from December 22, Spain has suspended entry into its territory of "citizens from the UK, except nationals or residents in our country," according to a communique published on Twitter.
The entry ban was scheduled to end on January 5.
"Border control in Gibraltar (the British Overseas Territory on Spain's south coast) will also be strengthened," the communique added.
As of Monday, Spain has confirmed 19 cases of the new coronavirus strain in six regions, many of the infected have previously entered Spain from the UK.
As the world is struggling to contain the pandemic, vaccination is underway in some countries with the already-authorized coronavirus vaccines.
Meanwhile, 232 candidate vaccines are still being developed worldwide -- 60 of them in clinical trials -- in countries including Germany, China, France, Russia, Britain and the US, according to information released by the World Health Organization on December 29.