Portugal on Thursday reported twin Covid records with 303 new deaths and 16,432 cases in a 24-hour period, prompting a decision to limit foreign travel to "special cases".
Of the total 11,608 deaths recorded so far in the country of some 10 million people, more than 3,000 have come during the last two weeks.
Travel abroad will be limited for two weeks starting Sunday, Interior Minister Eduardo Cabrita told parliament.
"Except for special cases, for the next two weeks, national citizens' departures by air, land or sea will be limited," he said.
According to data compiled by AFP, Portugal over the last two weeks has recorded the largest number of infections and deaths relative to its population of any country in the world, aside from the nearby British enclave of Gibraltar.
One hospital in the Lisbon suburbs had to urgently transfer more than 100 patients between Tuesday and Wednesday due to problems with its oxygen supplies.
"Clearly things are going very badly," Prime Minister Antonio Costa said in an interview on national television Wednesday evening.
"We have seen an exponential growth in new cases, and that leads to new hospitalisations which in turn put giant pressure on the national health service," he said, adding: "This tension will certainly last several weeks."
Nevertheless the number of people in hospital decreased on Thursday, to 6,565 including 782 in intensive care, for the first time since the start of the year.
Portugal went into a second nationwide lockdown on January 15.
Costa said the virus has surged since the beginning of the year due to the spread of the new, more infectious variant that initially emerged in Britain as well as an easing of measures over the Christmas holiday.
"If we had learned in time of the existence of the British variant, we would surely have taken different measures for the Christmas period," Costa said.