Edited (15.03.2018) - thanks @Joseph Webber

First, you have to install libphonenumber-js, which is a wrapper of google-libphonenumber ready to be imported on Angular 2+. You can install it on your app with:

npm install libphonenumber-js --save

or

yarn add libphonenumber-js

depending on the package manager you use.

After install you can use it on your component like:

import { Component, OnInit } from '@angular/core';
import { parse, format, AsYouType } from 'libphonenumber-js';


@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {

  asYouType: any;
  format: any;
  parse: any;

  ngOnInit() {
    this.asYouType = new AsYouType('US').input('2133734');
    this.format = format('2133734253', 'US', 'International');
    this.parse = parse('(0777) 844 822', 'RO');
  }

}

I added the working demo on Github:

libphonenumber-demo-angular2

I have found a solution currently:

1. You need google-libphonenumber and also types for it:
   npm install --save google-libphonenumber
npm install --save-dev @types/google-libphonenumber

2. Import PhoneNumberUtil, PhoneNumber into your validator file (full content):

import { ValidatorFn, AbstractControl } from '@angular/forms';
import { PhoneNumberUtil, PhoneNumber } from 'google-libphonenumber';

const phoneNumberUtil = PhoneNumberUtil.getInstance();

export function PhoneNumberValidator(regionCode: string = undefined): ValidatorFn {
  return (control: AbstractControl): { [key: string]: any } => {
    let validNumber = false;
    try {
      const phoneNumber = phoneNumberUtil.parseAndKeepRawInput(
        control.value, regionCode
      );
      validNumber = phoneNumberUtil.isValidNumber(phoneNumber);
    } catch (e) { }

    return validNumber ? null : { 'wrongNumber': { value: control.value } };
  }
}

3. Use PhoneNumberValidator in reactive form with your default region code (part of code):

import { PhoneNumberValidator } from '@app/validators';
...
ngOnInit(): void { ...
this.editPhoneForm = this.formBuilder.group({
  id: [''],
  phone: ['', [
    PhoneNumberValidator('US')
  ]],
}); ...

Your package configuration is incorrect. It needs to point at the source file for libphonenumber-js. Need to update the references to match your project structure.

Try this:

(function (global) {
    System.config({
        paths: {
            // paths serve as alias
            'npm:': './node_modules'
        },
        // map tells the System loader where to look for things
        map: {
            // our app is within the app folder
            app: 'app',
            // other references
            'libphonenumber-js': 'npm:libphonenumber-js'
        },
        // packages tells the System loader how to load when no filename and/or no extension
        packages: {
            app: {
                main: './main.js',
                defaultExtension: 'js'
            },
            // other references
            'libphonenumber-js': {
                main: 'libphonenumber-js.min',
                defaultExtension: 'js'
            }
        }
    });
})(this);