奥巴马呼吁美俄削减核武器数量
US President Barack Obama is to use his speech at Berlin's Brandenburg Gate to propose cuts of one-third in American and Russian nuclear arsenals, US officials say.
美国总统奥巴马将在柏林勃兰登堡门发飙演讲，建议美俄两国削减1/3的核武器。
They say he will also call for reductions in the number of tactical warheads deployed in Europe.
Before that, he will hold talks with Chancellor Angela Merkel.
Mr Obama's visit comes after G8 leaders backed calls for holding Syrian peace talks in Geneva "as soon as possible".
'Call to action'
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.
His 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 first due to have talks with Germany's chancellor, Angela Merkel.
In his speech at the Brandenburg Gate, Mr Obama 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.