Berlin  - Barack Obama's pending visit to Europe to increase his foreign policy profile ahead of the US presidential elections in November has set the rumour mills churning in Berlin.

The online edition Der Spiegel news magazine reported Tuesday the Democratic Party candidate aimed to make a major speech on US-European ties at Berlin's historic Brandenburg Gate.

The speech would pledge greater US cooperation with Europe than under President George W Bush, while at the same time calling for a greater contribution in Afghanistan and Iraq, where US troops are bogged down in drawn-out conflicts, the respected weekly predicted.

"The senator has often been criticized for not showing sufficient interest in Europe," an unnamed Obama adviser told Der Spiegel.

"This visit is an answer to the criticism and for this reason he will address this theme."

The Illinois senator could use his stops in London and Paris to speak on US-European relations, but his campaign team was thought to be behind the Brandenburg Gate venue, the magazine said.

The gate, which stood just inside the communist side of the Berlin Wall, occupies a fixed place in Cold War mythology.

It was here that in 1987 President Ronald Reagan urged the Soviet Union's last communist leader: "Mr Gorbachev, open this gate! Mr Gorbachev, tear down this wall!"

A little more than two years later, the wall did in fact come down.

Berlin was the venue for another famous speech by a former US president.

John F Kennedy made his famous "Ich bin ein Berliner" (I am a Berliner) in 1963, less than two years after the wall went up, although he was speaking not at the Brandenburg Gate but on the steps of a large city hall not far away.

According to the reports, July 24 has been pencilled in for Obama's visit to the German capital, although there has been no confirmation from either Obama's campaign office or the German authorities.

The Obama campaign team is said to hope that "television pictures of 100,000 cheering supporters" listening to the senator in Berlin would boost his election chances by showing that relations with Europe would improve under an Obama presidency.

Merkel could also benefit from being seen with the charismatic senator.

A weekend poll showed that 72 per cent of Germans would vote for Obama if they had the chance, against just 11 per cent for his Republican Party rival John McCain.

But there are also doubts. An unnamed official in Chancellor Angela Merkel's office told Der Spiegel that the Brandenburg Gate should not be turned into a backdrop for foreign election campaigns.

The decision in any case falls to the government of Berlin and not to the federal government.

And the chancellery made plain to Der Spiegel that while Obama would receive a warm welcome, so would McCain. (dpa)