US Secretary of State John Kerry will meet senior officials in China late this week, and then stop in Seoul for talks with South Korean leaders, the State Department announced Monday.

Kerry will make the Asia trip after high-stakes talks in Russia due Tuesday with President Vladimir Putin, where the tensions over Ukraine, the Iran nuclear negotiations and Syria will be addressed.

During May 16-17 talks in Beijing, America's top diplomat "will meet senior leaders of the Chinese government to advance US priorities ahead of the Strategic and Economic Dialogue this summer and the planned visit to the United States of President Xi Jinping this fall," State Department acting spokeswoman Marie Harf told reporters.

Kerry's visit follows accusations by US defense officials that China has dramatically ramped up its land reclamation efforts in the South China Sea this year.

The unprecedented rapid construction of artificial islands in the strategic waters comes to 2,000 acres (800 hectares), with Beijing expanding acreage "on the outposts it occupies by some 400 times," a US defense official said.

That revelation came as the Pentagon released its annual report to Congress on the state of China's military, which repeated accusations that Beijing was staging cyber attacks to scoop up information on American defense programs.

In Seoul, Kerry will sit down with South Korean President Park Geun-hye and Foreign Minister Yun Byung-se to discuss global, regional and bilateral issues as well as Park's upcoming visit to the United States, Harf said.

The visit comes two months after a bizarre attack in Seoul in which an activist slashed the US ambassador to South Korea in the face, sending him to the hospital for dozen of stitches. The assailant has been charged with attempted murder.

The issue of trade could figure in the talks in both countries, as the United States is seeking to finalize a massive trade pact with 11 Pacific rim countries, but not including China or South Korea.