Q: The US National Security Adviser John Bolton, according to Taiwan's "foreign ministry", had talks recently with his Taiwanese "counterpart", the first time since 1979 there has been such a high-level contact between US government officials and Taiwanese officials. Has China already complained about this meeting to the US?
Before answering your question, I need to correct you on one point. In light of the US government's explicit recognition of the government of the People's Republic of China as the sole legal representative of China and its commitment to unofficial exchange only with Taiwan, Mr. David Lee is by no means the "counterpart" of Mr. Bolton.
As to the incident you referred to, China deplores and strongly objects that. As we have repeatedly stated, the one-China principle is the political basis for China-US relations. We are firmly against the US engaging in any official contact with Taiwan in whatever form and under whatever pretext. We also stand resolutely against any attempt to create "two Chinas" or "one China, one Taiwan". This is our clear and consistent position. Once again we urge the US side to honor its commitment to the one-China principle and the three China-US joint communiques, stop having official exchange or upgrading substantive relations with Taiwan, and prudently and properly handle issues relating to it to avoid affecting China-US relations and bilateral cooperation in key areas.
Someone’s or something’s counterpart is another person or thing that has a similar function or position in a different place. 职能（或地位）相当的人；对应的事物
The foreign Secretary telephoned his Italian counterpart to protest. 外交部长致电意大利外长表示抗议。
The Finnish organization was very different from that of its counterparts in the rest of the Nordic region. 芬兰的这一机构和北欧其他国家的同类机构迥然不同。