The United States and China will on Wednesday try to find common ground on rows ranging from hacking to trade access, with few expectations of breakthroughs.

Senior officials will hold talks Wednesday and Thursday in Washington in the Strategic and Economic Dialogue, billed as the main annual meeting between the world's two largest economies.

The two sides prepared for the talks with a first-of-a-kind separate session Monday on cyber security, which has emerged in the past year as one of the biggest irritants in relations.

A US official said that the United States and China presented "practical proposals" on cyber issues but offered few other details.

The United States has accused China of waging a vast cyber espionage campaign that has cracked trade and government secrets, with a recent study estimating that US businesses lose hundreds of billions of dollars a year due to copyright theft.

China has hit back that it is the victim itself of hacking, charges that gained momentum when US intelligence leaker Edward Snowden said that US spies have broken deep into the rising Asian power's Internet network.

US officials said that they would renew charges that China has not sufficiently opened its vast market to foreign competition and that its currency, while rising, remains unnaturally low so as to boost exports.

In a joint letter, top lawmakers on economic policy from the two major US parties accused China of failing to live up to promises made in previous years.

"We remain very concerned that China has halted -- and in many cases reversed -- its market reforms," the four lawmakers wrote.

The lawmakers complained that China has not taken measures to back up promises to protect intellectual property. In one instance, they said they were not convinced that Beijing has fulfilled promises to ensure that all government offices run on legal instead of pirated software.

The letter was signed by Representatives Dave Camp and Sandy Levin, the top Republican and Democrat on the powerful House Ways and Means Committee, as well as Orrin Hatch and Max Baucus, the top Senate Finance Committee members from the two parties.

The talks follow on an informal weekend summit last month at a California desert resort between US President Barack Obama and his new counterpart Xi Jinping, who is expected to lead China over a decade in which it surpasses the United States in the size of its economy.

Experts said that the Strategic and Economic Dialogue will likely also remain general in tone as the four main participants are all new in their jobs.

"I think neither side sees concrete deliverables as key to this particular meeting," said Ken Lieberthal, a senior fellow at the Brookings Institution who was former president Bill Clinton's top adviser on Asia.

Secretary of State John Kerry, one of the four main participants, was kicking off the talks with a dinner Tuesday after flying in from Boston, where his wife was hospitalized.

Officials said that Kerry's participation in the talks would be determined based on the health of his wife, Teresa Heinz Kerry, who suffered seizure-like symptoms on Sunday.

A US official said that Kerry planned to raise concerns with China about human rights, including on the status of ethnic minorities.

Dozens of Tibetans rallied Tuesday outside of the White House, waving flags and demanding that the Obama administration put a priority on what they described as repression by China.

More than 110 Tibetans have set themselves alight since 2009 in protest over China's rule. Overseas groups said that Chinese forces opened fire on Tibetans who celebrated Saturday's birthday of their spiritual leader the Dalai Lama, who has lived in exile in India since 1959.

Last year's Strategic and Economic Dialogue was overshadowed by a row after Chen Guangcheng, one of China's most prominent activists, escaped house arrest for the safety of the US embassy days before the arrival in Beijing of Hillary Clinton, then the secretary of state.

The United States and China largely avoided public comment on Chen but negotiated a deal in which he was able to move to New York to study.

"If there's a lesson to be learned from the last Strategic and Economic Dialogue, it's that being visibly tough on human rights issues is wholly compatible with making progress on other bilateral concerns," said Sophie Richardson, China director at Human Rights Watch.