"With the passage of seven years, I can see that reconstruction of the affected region is steadily making progress," the prime minister said at a memorial ceremony in Tokyo.
But he also admitted that sufferings caused by the disaster are still carrying on.
"Many people continue to endure uncomfortable lives for seven long years. There are also many people who have no prospect of ever being able to return to their homes," Abe said.
He promised to continue to undertake reconstruction but did not mention the cleanup work of the Fukushima nuclear plant which is expected to take generations with hefty costs and unsolved technical problems.
A 9.0-magnitude earthquake in 2011 triggered a massive tsunami which destroyed the emergency power and then the cooling system of the Fukushima Daiichi nuclear power plant, and caused a serious nuclear disaster, forcing some 300,000 people to evacuate.
As of March 9, 2018, the triple disasters have left 15,895 people dead, 2,539 missing, and 73,349 living as evacuees.
Government data also showed that as of the end of September last year, at least 3,647 people had died due to health problems and other reasons while they were evacuees.
Fukushima Governor Masao Uchibori told a press conference earlier this week that the evacuation zone that equaled to some 1,600 square kilometers in 2011, accounting for 12 percent of the whole prefecture, has been reduced to 370 square kilometers, some 2.7 percent of the prefecture.
However, according to local government statistics, only 15 percent of the evacuees chose to go back home after the evacuation order was lifted in their hometowns.
Due to aftermaths of the 2011 disaster, the population of Fukushima prefecture decreased by some 14,800 people compared to before the earthquake, to 187.6 million as of Feb. 1, 2018, according to Uchibori.