es6 module with es5 target

index.js

import * as path from 'path';
function foo() {
    return import('leaflet').then(function (mod) {
        console.log(mod);
    });
}
;
console.log(path);
console.log(foo);

index.ts

import * as path from 'path';

function foo(): Promise<void> {
  return import('leaflet').then(mod => {
    console.log(mod);
  });
};


console.log(path);
console.log(foo);

tsconfig.json

{
  "compilerOptions": {
    "declaration": true,
    "noImplicitAny": true,
    "noEmitOnError": true,
    "noUnusedLocals": true,
    "module": "esnext",
    "moduleResolution": "node",
    "target": "es5",
    "outDir": "./lib",
    "lib": ["ES5", "ES2015.Promise", "DOM", "ES2015.Collection"]
  },
  "include": ["src/*"]
}