The BBC News Channel should not be compromised by budget cuts, the corporation's governing body has said.
In a review of the service, the BBC Trust warned that planned savings measures should not affect the "range and depth of stories" it covers.
However, it praised the channel's reputation on breaking news, and highlighted its growing audience.
The trust said BBC Parliament is seeing record audiences but must provide more contextual information on screen.
The BBC Trust conducts regular "service reviews" of the corporation's stations, which it uses to review progress and shape licence requirements for the future.
Looking at the BBC News Channel, it said that nearly 20% of UK adults had tuned in during 2010-11, up from 11.5% in 2006-7.
It said audiences expected the network to primarily cover breaking news, and noted that audiences peaked during major events.
However, the report noted that the market for breaking news was becoming increasingly crowded - both on TV and online.
Accordingly, it said the BBC should "continue to go beyond the headlines" and report stories "that do not receive widespread coverage elsewhere".
At the same time, the BBC is proposing changes to the News Channel, as part of its belt-tightening exercise after receiving a lower-than-expected licence fee settlement.
The trust agreed that a requirement to send more than one presenter to the scene of a major international news story was superfluous, and removed the condition from the channel's service licence.
However, it warned that budget cuts, and the plan to merge BBC News with the World Service "should not reduce the News Channel's ability to explain often complex and fast-moving international stories in a compelling way for all audiences".
BBC trustee David Liddiment, who led the review, said: "The past year has seen some hugely significant news stories - from the summer riots and Royal wedding at home, to the Japanese earthquake and Arab Spring uprisings abroad - and audiences tell us that for big national stories the News Channel is their 'go-to' service.
"Despite this strong performance, the News Channel must keep seeking new ways to improve and innovate.
"It is vital that the channel uses its resources wisely and maintains its distinctiveness and quality."
Reviewing BBC Parliament, the Trust said audiences view the channel as "unique", and particularly appreciated the chance to see parliamentary proceedings "first hand".
However, it noted that "parliamentary timings and processes can be confusing, even to those with a working knowledge of the institutions" and said that, although the BBC often provided information such as the name of a speaker, or the topic of a debate, this could be improved to "better meet the needs of audiences".
This would include on-screen tickers and suggesting relevant pages on the BBC Democracy Live site.
The trust also recommended that the BBC's main news bulletins should trail coverage of parliamentary debates on BBC Parliament more frequently.