RANCHO MIRAGE - Barack Obama and Xi Jinping headed Friday to a desert oasis for an unusually relaxed US-China summit as the two presidents looked to forge a bond that could shape relations for years.

Allegations that China has waged a cyber-hacking campaign against the United States are likely to dominate the talks, which will also take up the constant trade niggles that have soured ties between the world’s two largest economies. But Obama also has a wider purpose - trying to glean the strategic vision of the man set to guide a fast-growing China through the rest of his own presidency, with major effects on Obama’s own foreign policy legacy.

Xi makes his first trip to the United States as president months after taking control of the full machinery of the Chinese state, with US experts surprised at how quickly he has consolidated his power.

The 59-year-old holds credibility as the son of one of China’s founding revolutionaries and speaks in a confident, free-flowing style, a shift from the stilted formality of his predecessor Hu Jintao that frustrated the White House.

The two leaders had not been expected to meet until the G20 summit in Russia in September. But both sides, sensing uncertainty seeping into a complicated and often difficult relationship, saw value in an earlier encounter.

The presidents will ditch the stuffiness and convention of normally minutely planned US-China summits, and meet at a sumptuous retreat in a sun-scorched corner of California known as Sunnylands.

“Early in the term of both presidents, we felt that having this type of wide-ranging, informal setting for discussions between the two leaders would allow them to cover the broadest possible agenda,” said a US official.

Ahead of the talks, activists and family members of political prisoners incarcerated in Chinese jails called on Obama to make human rights a priority at the talks.

“President Obama should stop the trade-centered diplomacy and instead make it a human rights-centered diplomacy,” said Chen Guangcheng, the blind activist who escaped house arrest for the US embassy in Beijing last year.

Hours ahead of the summit, Chen’s brother said that China had granted passports to him and his mother so that they could see Chen Guangcheng.

Advocacy groups have pressed Obama to urge the release of 16 key prisoners, hoping that the summit will give Xi a specific target on human rights.