The LG G6 H870 has been spotted in FCC filing which revealed the Frequency Bands and Network Compatibility of the device.
The LG G6 H870 under test has several model variants, namely the LG H870, LG-H870S,LGH870DS and LG-H870K. According to FCC documents, The LG G6 H870 supports GSM 850/1900, WCDMA (UMTS) Bands B2, B4, B5 and LTE bands B2,B4, B5,B7,B12, B13 and B17. See the screen shots below for details.
Please check the accurate Network Compatibility of LG H870 at LG official website before you making purchase decision.
You can also find the LG H870 test report at FCC here.