* Confirmed cases of coronavirus jump to almost 1,700
* Government promises to help struggling economy
* Turkey bans flights to Italy; U.S. and Japan urge caution
ROME, March 1 (Reuters) - The death toll from an outbreak of coronavirus in Italy has risen to 34, five more than a day earlier, officials said on Sunday, as the government prepared to boost spending to help the fragile economy.
The head of Italy's Civil Protection Agency said the cumulative number of confirmed cases of the virus had jumped to 1,694 from 1,128 on Saturday, virtually all of them coming to light since Feb. 20 in the worst such contagion in Europe.
Of that number, 83 people had fully recovered, while 140 patients were in intensive care. The vast majority of those who have tested positive have few, if any symptoms.
Around 90% of all cases are concentrated in the wealthy northern regions of Lombardy, Veneto and Emilia Romagna. The government has ordered that schools and universities must remain closed there for a second week, with large public gatherings still banned in an effort to halt the contagion.
As the human toll grows, the government is increasingly worried about the economic outlook. Economy Minister Roberto Gualtieri announced the cabinet would approve this week 3.6 billion euros ($3.5 billion) of measures to help companies.
This came on top of an aid-package worth 900 million euros that was unveiled on Friday for the worst-impacted zones.
"I want to reassure Italians that we are well aware of the problems and dangers," Gualtieri said, adding that if additional help was needed it would have to come at a European level.
Opposition politicians said the proposals were far too limited, with the head of the far-right League, Matteo Salvini, demanding "at least 20 billion euros" of additional spending.
One of the hardest hit sectors is likely to be tourism, which accounts for 13% of gross domestic product, with hotels reporting mass cancellations even in cities with few or no coronavirus cases, such as Rome.
Underscoring the challenges, Turkey on Sunday banned all flights to and from Italy, while both the United States and Japan advised their citizens not to travel to swathes of the north, including tourist hotspots like Venice and Verona.
Cinemas, discos and theatres, including Milan's prestigious La Scala opera house, must remain shuttered in the three hardest-hit regions for a further week, while museums will be allowed to reopen to a limited number of visitors.
For the first time, a church in the heart of Rome announced that it was closing as a precautionary measure after a priest who had been working there came down with the virus.
The St. Louis of the French in Piazza Navona is particularly popular with tourists because it houses paintings by Caravaggio.
A Roman Catholic news agency said the 43-year-old priest had returned to Paris by car in the middle of February and tested positive for the virus on Friday. Only two cases of the disease have come to light so far in Rome -- two Chinese tourists in January -- and it was not clear where the priest was infected.
Pope Francis said on Sunday he had a cold and would have to skip a week-long Lenten spiritual retreat for the first time in his papacy. The Vatican has played down speculation he might have coronavirus, saying he only had a "slight indisposition".
The contagion has also hit the sporting world, forcing the cancellation this weekend of five top flight Serie A matches, which followed a similar disruption last week.
The chief executive of Inter Milan, which is vying for the Serie A title, warned on Sunday that the season might not finish at all if any more matches are postponed. (Additional reporting by Elvira Pollina in Milan. Editing by Jane Merriman)