China welcomes the prospect of a visit by the United States secretary of state, and both countries are in communication over related matters, the Foreign Ministry said on Monday.

"China welcomes US Secretary of State Rex Tillerson to pay a visit to China at a time convenient for both sides," Foreign Ministry spokesman Geng Shuang told a daily media briefing in Beijing, without giving further details.

The US State Department did not reply to a request for confirmation as of Monday evening.

Observers of China-US relations in Beijing said the maiden trip is part of ramped-up efforts to enhance "regular high-level engagement" between the two countries and would "set the tone" for future bilateral exchanges.

Tillerson is likely to go to Asia later this month, visiting Japan, the Republic of Korea and China, possibly meeting Foreign Minister Wang Yi and even more senior Chinese leaders, Japanese media reported on Saturday.

He is expected in Japan on March 17-18 and will meet Japanese Foreign Minister Fumio Kishida, Kyodo News Agency reported.

Wang Dong, an associate professor of international studies at Peking University and secretary general of the Beijing-based think tank Pangoal Institution, said Tillerson's likely trip to China bodes well for the joint efforts to build "regular high-level engagement" between the two countries.

Unlike US Defense Secretary James Mattis' visit to Tokyo and Seoul last month, Tillerson adds Beijing to his itinerary in an attempt to balance and elaborate on Washington's Asian policy, said Wang.

"Tillerson's stay in Beijing is expected to convey a message that the Trump administration is recalibrating its China policy by 'returning to normal' and paving the way for further cooperation," he said. That Trump has come to uphold the "one-China principle" as his predecessors did and accept the fact that it is non-negotiable greatly alleviated uncertainty surrounding China-US relations, he said.

Li Haidong, a professor of US studies at China Foreign Affairs University, said, "Tillerson's visit, if realized, will pave the way for a meeting between the two countries' top leaders, where they could express their core concerns face to face."

The burning nuclear ambition of the Democratic People's Republic of Korea and the country's frequent long-range ballistic missile tests are among Washington's top security concerns, Li said.

The DPRK test-fired four ballistic missiles into eastern waters early on Monday as combined forces of South Korea and the US launched joint military exercises last week, Xinhua reported.

The reported travel to China seemed to be a response to an invitation from China's top diplomat, State Councilor Yang Jiechi, last Tuesday.

Mo Jingxi contributed to this story.