あいにくですが。

The word 'あいにく' (ainiku) is an adverb that means 'unfortunately,' 'I'm afraid,' or 'it's too bad.' It's often used when delivering bad news or declining a request in a polite manner. The 'ですが' (desu ga) at the end adds a further level of politeness and can be translated as 'but' or 'however,' implying that while the news is unwelcome, there might be more to the situation or that the speaker regrets having to deliver it. The origin of 'あいにく' is thought to be a combination of 'あいに' (aini), meaning 'to meet' or 'to encounter,' and 'にくい' (nikui), an adjective suffix indicating difficulty or unpleasantness. So, it literally conveys the sense of 'difficult to encounter' or 'unfortunate encounter.' Over time, it evolved into its current usage to express regret or unfortunate circumstances. The earliest written records of a similar phrase date back to the Edo period (1603-1868).