奥巴马将与乌克兰总统波罗申科举行会谈
US President Barack Obama is to discuss economic support for Ukraine when he meets President-elect Petro Poroshenko in Warsaw.
美国总统奥巴马将与乌克兰总统当选人佩特罗·波罗申科在华沙碰面，商讨对乌克兰进行经济援助。
Mr Obama has said he will offer US support as Kiev tries to settle a gas bill with Russian supplier Gazprom, which has threatened to cut supply.
Ukraine's struggling economy has been in recession since 2012.
Mr Obama is in Poland for celebrations marking the 25th anniversary of the end of communism there.
But his visit has taken on extra significance following Russia's annexation（合并） of the Crimean peninsula in March. The move has left East-West relations at their lowest ebb since the Cold War.
Mr Obama is seeking to reassure East European allies that Washington will support them in the event of any Russian "provocation（挑衅）".
On Tuesday he pledged $1bn to boost military deployments to Europe in response to Russian actions in Ukraine.
Nato has also promised to bolster（支持） its defence capabilities.
The BBC's Adam Easton in Warsaw says Mr Obama chose to come to Poland for its symbolic value.
In a speech in Warsaw on Wednesday, he is expected to say that 25 years ago it faced similar problems to those facing Kiev today, but overcame them.
The message is that with the West's support, Ukraine can too, our correspondent says.