<script src="https://unpkg.com/imask"></script>

<input type="tel">
<input type="tel"><input type="tel"><input type="tel"><input type="tel"><input type="tel">

var items = document.querySelectorAll('input[type="tel"]');

items.forEach(function(el) {
  var dispatchMask = new IMask(el, {
    mask: [
      {
        mask: '+7 (000) 000-00-00',
        startsWith: '7',
        lazy: false,
        country: 'Russia'
      },
      {
        country: 'Azerbaijan',
        mask: '+994 (00) 000-00-00',
        lazy: false,
        startsWith: '994'
      },
      {
        country: 'Armenia',
        mask: '+374 (00) 000-000',
        lazy: false,
        startsWith: '374'
      },
      {
        country: 'Belarus',
        mask: '+375 (00) 000-00-00',
        lazy: false,
        startsWith: '375'
      },
      {
        country: 'Kazakhstan',
        mask: '+7 (000) 000-00-00',
        lazy: false,
        startsWith: '7'
      },
      {
        country: 'Kyrgyz',
        mask: '+996 (000) 000-000',
        lazy: false,
        startsWith: '996'
      },
      {
        country: 'Moldova',
        mask: '+373 (000) 000-00',
        lazy: false,
        startsWith: '373'
      },
      {
        country: 'Tajikistan',
        mask: '+992 (00) 000-0000',
        lazy: false,
        startsWith: '992'
      },
      {
        country: 'Uzbekistan',
        mask: '+998 (00) 000-0000',
        lazy: false,
        startsWith: '998'
      },
      {
        country: 'Ukraine',
        mask: '+380 (00) 000-0000',
        lazy: false,
        startsWith: '380'
      },
      {
        mask: '+(000) 000-00-00',
        startsWith: '',
        country: 'unknown'
      }
    ],
    dispatch: function (appended, dynamicMasked) {
      var number = (dynamicMasked.value + appended).replace(/\D/g,'');

      return dynamicMasked.compiledMasks.find(function (m) {
        return number.indexOf(m.startsWith) === 0;
      });
    }
  }
)
});