add-surchages-based-on-delivery-country.php

/**
 * Add a 1% surcharge to your cart / checkout based on delivery country.
 * Taxes, shipping costs and order subtotal are all included in the surcharge amount.
 */
function wb_woocommerce_custom_surcharge() {
	global $woocommerce;

	if ( is_admin() && ! defined( 'DOING_AJAX' ) ) {
		return;
	}

	$county     = array( 'US' );
	$percentage = 0.01;

	if ( in_array( $woocommerce->customer->get_shipping_country(), $county ) ) :
		$surcharge = ( $woocommerce->cart->cart_contents_total + $woocommerce->cart->shipping_total ) * $percentage;
		$woocommerce->cart->add_fee( 'Surcharge', $surcharge, true, '' );
	endif;

}
add_action( 'woocommerce_cart_calculate_fees', 'wb_woocommerce_custom_surcharge' );