Const ForReading = 1
Const ForWriting = 2

Set oFileSys = WScript.CreateObject("Scripting.FileSystemObject")
Set oFolder = oFileSys.GetFolder(".")

For Each file in oFolder.Files

    If Instr(file.name,".txt") > 0 Then

        Set objFile = oFileSys.OpenTextFile(file.path, ForReading)
        strText = objFile.ReadAll
        objFile.Close

        linesArray = Split(strText,vbCrLf)

        For each line in linesArray

            strNewText = strNewText & line & " | US" & vbCrLf

        Next

        strNewText = Left(strNewText,Len(strNewText)-2)

        Set objFile = oFileSys.OpenTextFile(file.path, ForWriting)
        objFile.Write strNewText
        objFile.Close
        strNewText = ""

    End If

Next