It took Barack Obama 30 minutes yesterday to whizz through the Forbidden City in Beijing following what was characterised as a candid three-hour discussion between the US president and Hu Jintao, his Chinese counterpart. At the end of his chilly tour Mr Obama exited through the Gate of Continuous Harmony.

He will doubtless be treated to the customary barrage of disharmony by conservative critics back home about having soft-pedalled in public on the human rights criticisms that normally arise during a US presidential visit.

But US officials insist that, in private, Mr Obama had “pulled no punches”. Jeff Bader, the president's senior Asia adviser, said Mr Obama gave Mr Hu the most frank talk on human rights he had heard in his 30 years of dealing with US-China relations.

At their joint appearance in the Great Hall of the People following their meeting, both leaders gave the impression that there had been sharp disagreements on a wide range of issues – in addition to Tibet, which Mr Obama finally raised, having hitherto gingerly sidestepped the troubled province.

Reading from separate statements, Mr Hu emphasised the need to “oppose and reject protectionism in all its manifestations”, which was code for having brushed off US complaints about China's large trade surpluses. Mr Obama referred to the need to move beyond the dollar-renminbi peg, which the Americans see as a form of Chinese mercantilism – again, signalling there had been little progress.

“I underlined to President Obama that, given our differences in national conditions, it is only normal that our two sides may disagree on some issues,” said Mr Hu, his hands firmly grasping the lectern. “What is important is to respect and accommodate each other's core interests and major concerns.”

It may take months, even years, to judge whether Mr Obama's approach of friendly strategic engagement with China will bear fruit in the form of more substantive Chinese assistance in helping America tackle what one US official called the “global headline issues”, such as climate change, nuclear weapons proliferation and economic imbalances.

Both countries eschew the term “G2”, for fear of offending other players. But in practice yesterday's long joint statement, which covered everything from clean energy to space technology, marked the attempted launch of a G2 global steering committee between the world's largest democracy and largest autocracy.

“There are really only two countries in the world that can solve certain issues,” said Jon Huntsman, the US ambassador to China and former Republican governor of Utah, whose fluent command of Chinese has already gone down well with his hosts. “So the meetings really have been aimed at co-ordinating like never before on the key global issues . . . There wasn't a single issue that was left out.”

Much like the long statements that the US and Soviet Union produced during their rare bouts of detente, however, a great deal of continuing disharmony could be read between the lines. In addition to the lack of progress on China's dollar link, the two sides evidently failed to reach common ground on the bulk of Mr Obama's agenda.

These included Afghanistan, which Beijing sees as a pointless war and which Mr Obama is about to intensify with a new surge of troops, and Iran, where the US leader promised “consequences” should Tehran fail to comply with international demands but on which Mr Hu was largely silent.

“China wants to see more dialogue on the Iran issue,” said Jin Canrong, of Renmin University. “We need more time to see if this approach is going to work.”

Both sides put a brave face on climate change. But announcements of a series of new clean energy initiatives, from carbon capture research to a project on electric cars, could not paper over the fact that both leaders had sharply downgraded prospects of a big deal on climate change in Copenhagen next month.

In concluding remarks, Mr Obama said: “The US welcomes China's efforts in playing a greater role on the world stage – a role in which a growing economy is joined by growing responsibilities.” It remains to be seen whether Beijing genuinely agrees with the second half of that statement.