More troops in Afghanistan: Obama 

US presidential hopeful Barack Obama called the situation in Afghanistan "precarious and urgent" and said Washington should start planning to transfer more troops there from Iraq.

The Illinois Democrat spoke from Afghanistan on the CBS program Face the Nation after meeting privately with Afghan President Hamid Karzai on an overseas trip meant to bolster his foreign policy credentials.

"We have to understand that the situation is precarious and urgent here in Afghanistan and I believe this has to be the central focus, the central front, in our battle against terrorism," Obama said.

Obama was spending Sunday night in Kuwait where he met the Gulf Arab state's emir, Sheikh Sabah al-Ahmad al-Sabah. He was due to fly on to Iraq for meetings on Monday.

He is also due to visit Jordan, Israel, Germany, France and Britain on a foreign tour he hopes will help answer Republican criticism that he lacks the experience to be commander in chief.

Berlin speech

The Obama campaign in Chicago confirmed he would deliver a speech on Thursday at Berlin's Victory Column, and not at the iconic Brandenburg Gate, their original idea for a venue.

German Chancellor Angela Merkel made clear she would frown upon using the Brandenburg Gate for "electioneering".

"It is my belief, which some people may think old-fashioned, that the Brandenburg Gate is linked to presidential speeches and if the candidate, or any other candidate is elected, then he will be most welcome to give a speech at the Brandenburg Gate," Merkel told German ARD television.

German media say tens of thousands of people could turn up to hear Obama speak. The senator is popular in Europe and an opinion poll published last week in the Bild newspaper found 72% of Germans would vote for him over Republican John McCain in the November 4 election if they could.

Obama said after meetings with commanders in Afghanistan that Washington should start planning immediately for a shift of American soldiers to the war with the Islamist Taliban from Iraq, where there are four times as many US troops.

"I think the situation is getting urgent enough that we have to start doing something now," Obama said.

Obama wants to send two more brigades, or some 7,000 U.S. troops, to Afghanistan and shift the emphasis from what he calls the Bush administration's "single-minded" focus on Iraq.

"There's starting to be a growing consensus that it's time for us to withdraw some of our combat troops out of Iraq, deploy them here in Afghanistan ... Now is the time for us to do it."

If the United States waited for a new administration to take office, it could take a year to boost troop levels, he said.

Admiral Michael Mullen, President George Bush's top military advisor as chairman of the Joint Chiefs of Staff, said the situation in Afghanistan was mixed, but not dire.

"I would not say in any way, shape or form that we're losing in Afghanistan," Mullen said on Fox News Sunday.

Asked about a hypothetical two-year timeline for a US military withdrawal from Iraq, he said he believed "the consequences could be very dangerous".