WooCommerce minimum order amount for subtotal only (don't include shipping+tax)

woo-gist.php

// Add to your functions.php file

add_action( 'woocommerce_checkout_process', 'wc_minimum_order_amount' );
add_action( 'woocommerce_before_cart' , 'wc_minimum_order_amount' );
 
function wc_minimum_order_amount() {
    // Set this variable to specify a minimum order value
    $minimum = 50;

    if ( WC()->cart->subtotal < $minimum ) {

        if( is_cart() ) {

            wc_print_notice( 
                sprintf( 'You must have an order with a minimum of %s to place your order, your current order total is %s.' , 
                    wc_price( $minimum ), 
                    wc_price( WC()->cart->subtotal )
                ), 'error' 
            );

        } else {

            wc_add_notice( 
                sprintf( 'You must have an order with a minimum of %s to place your order, your current order total is %s.' , 
                    wc_price( $minimum ), 
                    wc_price( WC()->cart->subtotal )
                ), 'error' 
            );

        }
    }

}

This method seems to work. Rather than calling the two hooks:

add_action( 'woocommerce_checkout_process', 'wc_minimum_order_amount' );
add_action( 'woocommerce_before_cart' , 'wc_minimum_order_amount' );

Use this instead:
add_action( 'woocommerce_check_cart_items', 'wc_minimum_order_amount' );

It will stop you reaching the checkout unless purchase requirement is met

Quick question:

How do i apply to this to international orders only. E.g. orders from America and canada I want to have it as minimum of 20 items need to be ordered. However for Australia have no minimum requirements?