In Europe, you cannot trade US ETFs anymore due to the ingenious new PRIIP regulation. Unless they come up with a "Key Investor Document", which almost none of them has. The regulation is in force since January, but only recently brokers have disabled US ETF trading for their European clients. This also affects the Z8 and Z9 systems. We'll put together alternative asset lists with European ETFs in the next time.

If you have to rebalance, do it as usual. It can't open new positions, but will reduce the old positions.