Britons vote in June on whether to remain part of the world's biggest trading bloc and Obama has previously said he wants Britain to stay in the EU and help maintain the post-war transatlantic partnership.
Most opinion polls show voters are split with a large number of people as yet undecided. Obama is due to attend a technology fair in Germany in late April and a source stated he would visit the British capital around that time.
"It would be pretty shocking if he didn't ask voters to stay in the EU," the source was quoted as saying.

Latest News from World News Desk