The top US official for Taiwanese relations arrived in Taipei late Sunday to brief authorities on US President Barack Obama"s recent trip to China, according to dpa. Raymond F Burghardt, chairman of the Board of Trustees of the American Institute in Taiwan (AIT), is scheduled to meet with President Ma Ying-jeou Tuesday to brief Ma on Obama"s talks with Chinese President Hu Jintao, the Central News Agency quoted an unnamed government source as saying. The US government"s stance on arms sales to Taiwan as well as the controversy surrounding Taiwan"s relaxation of regulations on US beef imports will also be raised during Burghardt"s talks with Ma and other Taiwanese officials, the source said. Many Taiwanese were concerned that Obama did not speak out for Taiwan on his China trip, which ended Wednesday. While Obama noted that US policy was based on the three US-China communiques and the Taiwan Relations Act, the act - in which Washington pledges to sell defensive arms to Taipei - was not mentioned in the Obama-Hu joint statement. In the joint statement, the US said it respects China"s sovereignty and territorial integrity, which further raised concern in Taiwan because China considers Taiwan to be Chinese territory. Taiwan"s opposition Democratic Progressive Party warned that Taiwan-US ties have regressed, and demanded the US clarify its stance on Taiwan. The US opted to officially recognize China, not Taiwan, in 1979, but passed the Taiwan Relations Act, pledging to continue to sell defensive arms to the island. Despite the lack of formal ties, the US remains Taiwan"s top arms supplier and one of the top trading partners of Taiwan, which is recognized by 23 mostly-small nations.