In this task, given a sentence in the Japanese language, your task is to convert it into the English language.

特に、合衆国のアップルストアとAT&Tストアおよびカナダにおいて、iPhoneを利用可能にするシステムが、ネットワークの故障および初日の販売に見合うだけのキャパシティに満たずに困難を期した。
Systems which enable the iPhones for service had difficulty due to network failures and insufficient capacity to meet the demand for first-day sales, particularly in the United States at Apple and AT&T stores, and in Canada.