First lady Akie Abe on Thursday questioned a plan to build high seawalls in coastal Tohoku areas impacted by the devastating March 11, 2011, tsunami.

Delivering the 15-minute keynote speech in English at the Ford Foundation in New York, the wife of Prime Minister Shinzo Abe noted local opposition to the barriers, which are already under construction.

"I am asking whether we could not adjust our plan to make it more flexible, reflecting the differences from region to region," Abe said, stressing she is "not an activist, opposed to the plan."

The seawalls could block ocean views, and the cost of maintaining the walls, which will not last more than 60 years, will fall on coastal communities with shrinking populations, she said.

A group of oyster farmers in Kesennuma, Miyagi Prefecture, is concerned that the wall there will block the nutrient-rich runoff from the forests that make the area good for cultivating oysters, she told the audience.

"A wall is dividing one heart from the other," the first lady said, referring to the division between residents of the disaster-hit areas who want the seawall to be built quickly and those who are hesitant and think more consideration is needed.

In a question-and-answer session after her speech, Abe said she has worked on the issue in Japan but has not gained much traction, so she decided to take the opportunity to speak about it overseas.

Abe has gained a reputation for being outspoken. Notably, she has voiced her opposition to exporting nuclear power technology, despite it being a centerpiece of her husband's strategy to revitalize the Japanese economy.

She was in New York with the prime minister, who participated in several days of high-level meetings and spoke at the U.N. General Assembly.