The British economy will be weaker and the European Union will be damaged if Britain votes to leave the European Union, the White House said Friday ahead of President Barack Obama’s scheduled visit.

Obama will strike a delicate balance over a British exit, the so-called Brexit, from the EU bloc, during his visit to Britain next week, where he will host a town hall with youth and offer his view “as a friend” that Britain should remain in the EU.

Earlier this week the International Monetary Fund Managing Director Christine Lagarde warned that the threat of Britain leaving the EU as "one of the serious downside risks on the horizon of global growth."

Lagarde said a vote by Britons in the June 23 referendum to leave the EU would cause widespread uncertainty, but added that she hoped it wouldn't happen.

"It's been a long marriage between members of the European Union. It's my personal hope that it doesn't break. And like [in] all marriages, good talks can actually help."

On Tuesday, the IMF cut its 2016 growth forecast for Britain to 1.9 percent from 2.2 percent and said the country could deal a damaging blow to the fragile world economy if it votes to leave the EU.

Last week, famed economist Nouriel Roubini warned that a split between the U.K. and the EU could accelerate a wave of independence movements across the continent, laying the groundwork for the end of the EU.

While opinion polls on the referendum suggest the result could be very close, most have come marginally in favor of an "In" win and betting firms are also pricing that in. One poll published Tuesday, however, showed the Leave campaign three points ahead.

After public opinion polls failed to predict a Conservative Party victory in Britain's 2015 parliamentary election, there is a great deal of uncertainty around their accuracy.

Data from Reuters were used to report this story.