WASHINGTON — Expectations are low as top officials of the United States and China prepare for an annual meeting here on Tuesday. Yet the fact that the two nations are talking at all is seen as positive at a time when they seem as far apart as ever, not least after the recent discovery that hackers linked to China have stolen the personal data of millions of federal workers.

The cyberattacks are certain to charge the atmosphere at the seventh such gathering, known as the U.S.-China Strategic and Economic Dialogue. But that issue will share a lengthy agenda with discordant matters of trade and open markets, the value of China’s currency, the treatment of American companies in China, Beijing’s military buildup in the South China Sea and more.

The high-level gathering is occurring as the Republican-led Congress, in a rare alliance with the Obama administration, is trying to revive legislation recently derailed by Democrats that would ease President Obama’s negotiation of a trade accord with 11 other Pacific Rim nations, excluding China.

While administration officials have said little in briefings with reporters that would raise expectations for breakthroughs between the world’s two biggest economic powers, the talks are nonetheless seen as potentially setting the table for agreements to be announced when Mr. Obama receives President Xi Jinping for a state visit in September. The meeting between the United States and China in Beijing last summer was the background for an announcement by the two presidents in November of a climate change accord.

Also, the White House sees China’s cooperation as important to the success of international negotiations with Iran to limit that country’s nuclear production, with a deadline for those talks set for the end of this month. China is considered critical to managing nuclear-armed North Korea, as well.

“The U.S. and China have a very complex, very consequential relationship,” said Daniel R. Russel, assistant secretary of state for East Asian and Pacific affairs. “We don’t always see eye to eye. But the fact is that global challenges require that we cooperate.”

On the eve of the two-day discussions, Secretary of State John Kerry and Treasury Secretary Jacob J. Lew hosted a dinner on Monday for their Chinese counterparts and other diplomats from both countries at Mount Vernon, the estate of George Washington. The joint roles of Mr. Kerry and Mr. Lew reflect the dual nature of the talks, which are to cover economic and national security issues.

But the evening’s hospitality was expected to give way by Tuesday morning to candid, tense exchanges, as the Americans confront the Chinese about cybersecurity. The United States has not accused the Chinese government of cyberattacks that siphoned off personal, financial and medical records of at least four million federal employees and perhaps millions more people, but government and private-sector officials have traced the invasions to one or more groups in China.

Separately, little progress is expected on a bilateral investment treaty, and the American side is split on how much effort to make on an issue unlikely to be concluded before Mr. Obama leaves office.

A special session is scheduled on the dispute over China’s claims in the South China Sea and its construction of outposts there. Mr. Russel called the buildup there “troubling not just to us, but to the countries in the region.”