James Harding has announced plans to draw up a "Future of BBC News" review in the next three months.
The head of BBC News has warned his staff of future cuts, saying: "We can't afford to do everything."
The division, which employs around 7,350 staff, needs to make £5m of cuts by 2016/17 and will contribute to £550m savings targeted by the corporation by 2021/22.
He said the task of the Future of BBC News project is to "present a plan of how we propose to meet BBC News' share" of these savings.
He also said plans for savings in BBC Online will be presented in "the findings of the Online Creative Review".
Last summer, the BBC announced it had discovered a £150m shortfall in funding from the licence fee it 2016/17. The corporation said it could deliver £50m in savings from “merging divisions, cutting down management layers, reducing managers and improving processes”. It said that more than 1,000 jobs would be lost as a result.
And it emerged in November that £5m of the total £150m savings sought would be footed by the news division.
In an email to staff at the time, Harding said BBC News would be investigating "how we compare with the rest of the industry" as it seeks to find where the cuts will come from.
And in a blog post of Friday, Harding said the organisation is set for a "defining year".
He said: "Technology is transforming the news. Audience expectations are changing, too. And the funding settlement for the BBC requires both cuts and the reallocation of spending.
"We are going to have to make choices.
"We’re going to start by opening up. We will share as much information as possible. Then, we’re going to listen hard. We’re going to encourage discussion across News of the options open to us. And, then, we’re going to choose. We will distill the ideas into a programme of reforms and investments.
"We start from a position of strength.
"But we can’t afford to do everything."
He added: "We’ve identified four main areas where we think we will need to consider changes.
"First, output. Where do we think people are going to watch, listen to, and get their news, and what do we want to do about it?
"Second, content. What can we do to tell the story better?
"Third, how do we ensure BBC News serves all audiences in the UK, regardless of age, identity, income, gender or geography? Young people are consuming less and less traditional media – how do we cater for them?
"And fourth, the way we work. How do we invest in people, reduce costs, increase opportunity and improve the working culture?
"Today, we have questions, not decisions. This is not an announcement of job cuts. It’s not even a statement on a savings target. It’s about setting our priorities."