Obama 'to call for' US-Russia nuclear weapons cuts

President Barack Obama speaks at the Brandenburg Gate

US President Barack Obama is to use his public speech in Berlin to propose cuts of one-third in American and Russian nuclear arsenals, US officials say.

They say he will also call for reductions in the number of tactical warheads deployed in Europe.
He met Chancellor Angela Merkel, who criticised the broad scope of the US surveillance programme known as Prism.
Mr Obama's visit comes after G8 leaders backed calls for holding Syrian peace talks in Geneva "as soon as possible".

Analysis

Jonathan Marcus BBC diplomatic correspondent

President Barack Obama is seeking to revive the process of nuclear disarmament which figured prominently during his first term but which has largely disappeared from the agenda since then.
Reducing the stockpiles of strategic or long-range nuclear weapons further is one thing - though without a resolution of US-Russian differences over missile defence, it may be difficult to make headway. Bringing shorter-range- so-called tactical nuclear weapons - into the picture could also be problematic.
Russia has an overwhelming preponderance of these weapons in Europe and has often seen them as tied to imbalances in conventional weaponry. Opening up that whole can of worms could be difficult.
There are, of course, ancillary benefits to arms reduction talks between Washington and Moscow. This is something they can engage in as equals, and success might have a broader positive impact upon their relationship. And as nuclear arsenals get smaller, how long will it be before those of the smaller nuclear players need to be counted in the mix?

This is Mr Obama's first visit to Berlin as American president.

US officials say he will seek cuts in US and Russian nuclear arsenals of one-third from the levels agreed in the New Start treaty in 2010.
Under New Start, each side is allowed a maximum of 1,550 warheads and no more than 700 deployed launchers.
The new limit on delivery systems is less than half the ceiling of 1,600 specified in the original Start treaty from 1991.
Mr Obama also wants to reduce the number of tactical nuclear weapons deployed in Europe - a move Russia has resisted in the past.
Such weapons are not covered by existing treaties.
Mrs Merkel criticised US phone and internet surveillance programmes, saying: "We do see the need for gathering information, but there is a need for due diligence and proportionality."
The chancellor grew up in Communist East Germany, where police surveillance was widespread.
She acknowledged that the internet "enables enemies of a free liberal order to use and abuse and bring threats to all of us", but "an equitable balance must be struck".
Mr Obama said the monitoring applied within narrow limits to do with national security. It had detected 50 potential threats and saved many lives, he emphasised.

"This is not a situation where we simply go into the internet and begin searching any way we want," he told a news conference in Berlin.

Speaking about the Syrian conflict, Mr Obama said the US was confident that the Syrian government had used chemical weapons during the 26-month-old conflict, but refused to spell out what aid might go the rebels.
"I cannot and will not comment on specifics on our programmes related to the Syrian opposition," he said, stressing his support for a political transition.
Mr Obama's address to students and government officials at the Brandenburg Gate comes almost 50 years after John F Kennedy's celebrated "Ich bin ein Berliner" speech.
He is expected to make what US officials describe as "a call to action", for the West to engage in major global issues.
He is also likely to speak in detail about ways of promoting democracy and ending conflicts as well as tackling climate change and nuclear proliferation.
When Mr Obama was last in Berlin in 2008, he spoke to an estimated 200,000 people about America's "mistakes" and how the Afghan people needed "support to defeat the Taliban".
He may now take the opportunity to explain why he has ordered peace talks with the enemy America has fought for 10 years, says the BBC's North American editor Mark Mardell.
After the G8 meeting in Northern Ireland, President Obama described the planned Taliban talks as "a very early step" towards reconciliation in Afghanistan.