At least eight more countries have been added to the list of 'high risk' countries by the United States Centers for Disease Control and Prevention (CDC) to discourage travel to these locations and contain the Covid-19 spread.
"Avoid travel to Spain," the CDC said in one of its travel warnings for the eight countries. Others include Finland, Chad, Lebanon, Bonaire, Gibraltar, Monaco and San Marino.
The US health watchdog also urged travellers to follow recommendations or requirements in the eight countries, including wearing a face mask and staying six feet apart from other individuals.
"If you must travel to Spain, make sure you are fully vaccinated before travel. Because of the current situation in Spain, even fully vaccinated travelers may be at risk for getting and spreading Covid-19 variants," the CDC further noted.
The US is facing another massive outbreak of coronavirus infections as the new Omicron variant raced ahead of other strains to become the dominant version of the coronavirus in the country. Omicron cases accounted for nearly 73 per cent of new infections as of last week, US federal health officials said on Monday.
Till the end of November, more than 99.5 per cent of Covid-19 cases were caused by Delta, the CDC data showed.
The CDC's travel alerts are usually for countries on 'Level 4' of Covid-19 outbreak, signifying "very high" risk.
Monday's alerts came as the Netherlands went into a lockdown this weekend while more European governments contemplated imposing additional Covid-19 restrictions ahead of the Christmas and New Year holidays.
Omicron was first reported by scientists in South Africa less than a month ago. On November 26, the World Health Organization designated it as a "variant of concern" due to its high rate of transmission. The mutant has since shown up in around 90 countries.