Is is possible import template tag with ES2015?

I'd been reading but I don't find anything if is it possible define in a different html file and import with ESModule to use with shadowRoot, could be?

index.html, where I define2 javscript modules and use my component <hello-world></hello-world>

<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>My First Component</title>
    <meta name="description" content="My First Component">
    <meta name="author" content="Ismael Rodriguez">
    <script type="module" src="js/my-template.js"></script>
    <script type="module" src="js/component.js"></script>
    <!--
        <template id="my-template">
            <h2>Hello World</h2>
         </template>
    -->
</head>

<body>
    <h1>Web Component</h1>
    <hello-world></hello-world>
</body>

js/my-template.js, In this module only export a string which has tags html.

export const template = `
    <style>
        h3 {
            color: red;
            font-family: helvetica;
        }
    </style>
    <h3>Hello World</h3>
`;

js/component.js, Finally import the module my-template.js. I have found this way to interpret the template from my module using ESmodule. How Could I import the template and use in my component (with firefox support)?

import {template} from './my-template.js';

class HelloWorld extends HTMLElement{

    constructor(){
        super();
        let shadowRoot = this.attachShadow({mode: 'open'})
        const t = this.createTemplate(template);
        const instance = t.content.cloneNode(true);
        shadowRoot.appendChild(instance);

        /*console.log(template);
        const t = document.querySelector('#my-template');
        const instance = t.content.cloneNode(true);
        shadowRoot.appendChild(instance);*/

    }

    createTemplate(html){
        const template = document.createElement('template');
        html = html.trim();
        template.innerHTML = html;
        return template;
    }
}

window.customElements.define('hello-world',HelloWorld);

You can only import Javascript files as ES6 Modules.

If you wan to import a element, you'll need to put it a Javascript file, for example by using a template literal string.

template.js:

export var template = `<template>
    <h1>Content title</h1>
    <div>Content</div>
  </template>`

But it doesn't make sense. Instead you could define the content template directly.

templates.js:

export var literal1= `
    <h1>Content title</h1>
    <div>Content</div>
  `

index.html:

<div id=host></div>
<script type="module">
    import * as templates from './templates.js'
    host.attachShadow( {mode:'open'} )
        .innerHTML = templates.literal1
</script>

Alternatly, if you want to keep your DOM element in a HTML file, you can use fetch() to import a file, as demonstrated by the code snipped in this post about HTML Imports.