China welcomes the new Philippine president to visit at an early date, the Foreign Ministry said, following reports that a visit is likely to take place in late October.

Ministry spokesman Lu Kang told a news conference on Friday that China has said many times that it would welcome a visit by President Rodrigo Duterte, and the two sides are in close communication.

"Differences will exist between any two countries, but ... there is no setback that cannot be overcome in the Sino-Philippine relationship as long as the two countries work to maintain the political will to solve their differences," Lu said.

According to diplomatic sources contacted by Japan's Kyodo News Agency, Duterte plans to visit China on Oct 19 and 20 and to embark on a "working visit" to Japan from Oct 25 to 27. These will be Duterte's first trips outside Southeast Asia since assuming office on June 30.

Kyodo also said that Duterte chose China as his first destination, instead of Japan, at the suggestion of Zhao Jianhua, the Chinese ambassador to Manila.

"I've noticed such reports, but I want to say that the Philippines is a sovereign state and it will decide its own diplomatic agenda according to its own judgment," Lu said.

Under its previous administration, the Philippine government unilaterally initiated an arbitration case over the South China Sea disputes against China in 2013, and the Arbitral Tribunal in The Hague issued a ruling in July. China has reiterated that it will not accept any proposition or action based on the decision.

During a speech on Thursday, Duterte said he will bring up the ruling in a constructive way on his China trip.

He also said he wanted to preserve goodwill with China to allow for economic partnership, according to media reports in the Philippines.

Chen Qinghong, a researcher of Southeast Asian and Philippine studies at the China Institutes of Contemporary International Relations, said signs indicate that Sino-Philippine ties are moving in the right direction.

However, he said both countries should be cautious of outside interference as they strive to improve their relationship.