A spokesman for China's Foreign Ministry on Friday expressed the country's appreciation for Australia's efforts in searching for the missing flight MH370.

Hong made the remarks at a regular press briefing after Australian Prime Minister Tony Abbott visited Shanghai and made disclosures on progress in locating the plane's black box.

Hong said China had noticed media reports that the search area of the black box had been narrowed, and that China began a joint search with Australia on Thursday in the area of about 58,000 square km defined by Australia.

Chinese patrol ship Haixun 01, Ministry of Transport vessels Donghaijiu 101 and Nanhaijiu 115 together with the Chinese navy's Kunlunshan, Jinggangshan and Haikou are searching the area, Hong said, adding that Haixun 31 and Nanhaijiu 101 of the Ministry of Transport and the Navy's Yongxingdao are still combing the eastern part of the southern Indian Ocean.

According to the spokesman, countries in the region have the capacity to cope with the challenge through their joint efforts and China is willing to work with all sides including Australia to speed up the search.

When asked if China is satisfied with Malaysian search work, Hong said Malaysia has coordinated with the international community to launch a large-scale search since the plane went missing on March 8.

China will strengthen coordination and assistance with Malaysia and Australia to continue the hunt for the missing plane, he added.

Abbott said in Shanghai on Friday that he is confident rescuers know the position of MH370's black box.

"We are confident that we know the position of the black box flight recorder to within some kilometers," Abbott said as he delivered an address at a luncheon in Shanghai.