The Argentinian ccTLD manager, nic.ar, is implementing new security and privacy enhancements and as a result will be offline for five days from 14 August, with normal service including the changes resuming on 20 August.
The ccTLD manager stopped support at 17:00 on the 14th and the new website with new enhancements will commence at 10:00 on the 20th.
More information in Spanish is available from the news report at www.fayerwayer.com/2013/08/no-se-podran-registrar-dominios-en-argentina-por-una-semana.