At a news conference later, Wang said: "We believe that without any disturbances from the outside, COC consultations will accelerate".
A code of conduct between Beijing and the Association of Southeast Asian Nations (Asean) to govern behaviour in the strategic South China Sea has been years in the making.
Asean-related meetings to be held in Singapore through Saturday will include foreign ministers not just from Asean but such countries as Australia, Canada, China, India, Japan, New Zealand, Russia, the USA and the two Koreas.
However, it was too early to say when negotiations would be complete, he added.
At Thursday's meeting, foreign ministers of the ASEAN member states as well as ministers of the observer countries, including Iran, Russia, China, and India, are scheduled to discuss the latest regional and global developments during the 51st session of the 10-nation bloc.
Despite the ridicule in China's state media, Beijing was quick to welcome the investment, expressing hope that the US, Japan and Australia would increase investment.
Pompeo wrapped up a full day with a meeting with Singapore's prime minister, Lee Hsien Loong, at the Istana in Singapore.
The suggestion to exclude outside countries "is obviously targeted at the United States which has been dominating the waters of the Western Pacific and the South China Sea in particular", Hoang Thi Ha, from the Asean Studies Centre, ISEAS Yusof Ishak Institute in Singapore, said.
USA intelligence agencies have said a Russian propaganda arm tried to tamper with the 2016 presidential election by posting and buying ads on Facebook.
Facebook said on Tuesday it had identified a new coordinated political influence campaign to mislead its users and sow dissension among voters ahead of November's U.S. congressional elections.
Pompeo was the first senior US official to visit Malaysia since Prime Minister Mahathir Mohamad took office following a May election dubbed "quite historic" by a senior State Department official.
One of Trump's early acts in office was to pull out of the Trans-Pacific Partnership (TPP) trade agreement, which involved four Southeast Asian states.
"As two members of the U.N. Security Council and the world's largest two economies, we should of course maintain talks at all times", Wang said.
Speaking on the event sidelines on Thursday, China's Wang Yi called for a push to establish a peace mechanism as well as denuclearisation.
And with China and Russian Federation, economic cooperation as part of Seoul's New Northern Policy.
The United States has said it will press Southeast Asia to keep up sanctions on Pyongyang during the meetings.