BERLIN (Reuters) - European leaders and President Barack Obama will discuss on Friday an extension of the sanctions imposed on Russia for its intervention in Ukraine, as well as possible new sanctions for its bombing in Syria, multiple sources familiar with the plans said.

The meeting in Berlin, hosted by Chancellor Angela Merkel and including the leaders of Britain, France, Italy and Spain, comes a little over a week after Donald Trump's victory in the U.S. presidential election.

Trump has indicated that he will seek a rapprochement with Russia, raising doubts in Europe about the future of the sanctions regime introduced by Washington and Brussels in 2014 following Russia's intervention in eastern Ukraine.

A German official said the plan was to agree a rollover of EU sanctions against Russia, which are due to expire at the end of January, in the coming weeks.

But there is concern that Trump might move in the opposite direction after his inauguration on Jan. 20th. European leaders will therefore be seeking clarity from Obama, who met with Trump at the White House for over an hour last week. Obama is due to arrive in Berlin on Wednesday evening after visiting Greece.

"We're in a really critical situation," said the German official. "We have to prevent a situation where the EU rolls over the sanctions and then the new U.S. president comes in and lifts them."

After his meeting with Trump, Obama sought to reassure U.S. allies that the president-elect would maintain core relationships around the world, including with NATO.

European officials fear that Russia will use the time before Trump's inauguration to launch new offensives in Syria and Ukraine. Two diplomatic sources said the issue of Syria would also come up at the Friday meeting in Berlin.

"Syria will definitely be on the agenda," said one of the sources, citing coordinated Russian missile strikes against rebels in Syria launched on Tuesday from an aircraft carrier in the Mediterranean.

The Kremlin has said it is maintaining a moratorium on air strikes in the city of Aleppo.

European Union leaders last month condemned Russia for its bombing of civilians in Aleppo and signaled that they could introduce new sanctions for its actions there if the bombing continued.

The Syrian opposition has been pressing Western countries to expand sanctions to include some Russian firms that are supplying weapons and bank notes to Syria.

Syrian opposition leaders are due to meet with EU leaders, including EU foreign policy chief Frederica Mogherini, in Brussels on Friday.

The second source said European leaders were keen to send a signal to Trump, making it more difficult for him to reverse U.S. policy and cozy up to Russia.

(Reporting by Noah Barkin)