Former Florida governor Jeb Bush called for closer trade and security ties with Europe on Tuesday (9 June) in a speech in Berlin, the first stop on a five-day tour designed to prove his foreign policy credentials before announcing his run for the presidency.

Bush's European trip, which will also take in Poland and Estonia, comes just before he launches his candidacy for the Republican presidential nomination in Miami next Monday (15 June).

Addressing some 2,000 politicians and business people at an economic conference organised by Chancellor Angela Merkel's conservative CDU party, Bush received a warm welcome, but it was a far cry from an address the then Senator Barack Obama gave in Tiergarten park in 2008 with more than 200,000 people cheering.

Merkel joined the conference shortly after Bush finished his speech and shook his hand, to applause from the audience.

"The EU and the United States have a common interest in the steady opening of markets across the world," Bush said in his speech.

"That's one reason why we need a serious plan to complete TTIP -- the Transatlantic Trade and Investment Partnership," he said, referring to an EU-US trade deal under negotiation.

"I'm a believer in this partnership and for the sake of jobs and economic opportunity I hope that we get this done at work speed," he added.

On global security, Bush stressed the continued importance of NATO, 70 years after the United States and western Europe began to build a post-war alliance.

"Who will say otherwise, as we watch the fate of Ukraine slowly unfold in tragedy?" Bush said, adding: "Our alliance, our solidarity and our actions are essential if we want to preserve the fundamental principles of our international order."

Bush has tried to differentiate himself from his brother George W Bush, arguably the most unpopular US president in Germany since the end of the World War Two, mainly because of his decision to invade Iraq in 2003.

Their father, George H W Bush, is more widely respected for his role in the events leading to the reunification of East and West Germany at the end of the Cold War.

In the United States, many conservatives remain unconvinced by Jeb Bush, Florida governor from 1999 to 2007. While he is at or near the top of Republican polls, he has been unable to pull away from a host of challengers for the nomination.