Obama urges Europe to stay united while in Germany

US President Barack Obama on Monday said the United States needed a strong, united Europe to maintain international order, and he urged European allies to increase defence spending to address DAESH and other security threats.

Paying an official visit to Germany that focused on boosting trade ties, Obama invoked Europeans to look past the multiple crises confronting their nations and maintain the unity that had brought peace to their continent.

His comments came after an earlier trip to London, where the American president insisted Britain to stay in the 28-nation European Union, boosting efforts by Prime Minister David Cameron to avoid a so-called "Brexit" that opponents warn could provoke damaging political and economic consequences.

For Britain's closest ally, EU membership amplifies British influence, facilitates trade for US companies and strengthens the 28-member bloc that Washington views as a pillar of stability in the post-World War Two era.

Opponents of the EU, many of whom laud the US alliance, have said that membership has shackled Britain to the corpse of a failed German-dominated experiment in European integration, and that Britain, if freed, could prosper as a sole trader.

"I've come here today to the heart of Europe to say that the United States and the entire world needs a strong and prosperous and democratic and united Europe," Obama said during a visit to a trade fair in the northern Germany city of Hanover, drawing applause from his audience.

Obama voiced worries over Russia's annexation of Crimea and slow economic growth, especially in southern Europe, had opened way to questions about integration on the continent and triggered destructive politics that stoked fears about immigrants and people with different religions.

An influx of refugees fleeing the civil war in Syria has sparked tensions within the bloc and put pressure on German Chancellor Angela Merkel, the preeminent leader in Europe, whose initial open door policy hurt her domestic political standing.

Obama's rare two-day trip to the trade fair was considered as a sign of backing for a leader with whom he has forged close ties ahead of German elections next year.

'Defining moment'

It also allowed him to put his support for Merkel and Cameron in the wider context of Europe's role in the world.

"This is a defining moment, and what happens on this continent has consequences for people around the globe," Obama said on Monday.

"If a unified, peaceful, liberal, pluralistic, free-market Europe begins to doubt itself, begins to question the progress that's been made over the last several decades, then we can't expect the progress that is just now taking hold in many places around the world will continue."

Obama has spoken out against similar trends in the United States. He did not conceal his disdain for Republican presidential front-runner Donald Trump, who has proposed setting up a wall on the US border with Mexico and temporarily banning Muslims from entering the United States.

Obama needs support from European allies to deal with foreign policy challenges in Russia and the Middle East, and he announced dispatching of an additional 250 US forces to Syria during his trip in Hanover.

Syrian opposition group the High Negotiations Committee said boosting the US military presence to 250 more would be "a good step" and help "rid our country of this scourge".

"But Syria will not be free of terrorism until we see the end of the Assad regime's reign of terror," added HNC spokesman Salem Al Meslet.

Meanwhile the president said Europe generally could do more to prepare for its own defence and to fight DAESH. He reiterated his call that NATO members step up their contributions and warned of a tendency to get complacent about defence needs.

"We need to stay nimble and make sure our forces are inter-operable and invest in new capabilities like cyber defence and missile defence," Obama added.

"That's why every NATO member should be contributing its full share, 2 percent of GDP, towards our common security - something that doesn't always happen and, I'll be honest, sometimes Europe has been complacent about its own defence."