Athen's missile deployment, paid for by Saudi Arabia, will "protect critical energy infrastructure", Petsas told reporters.The announcment comes a week after Iran-backed Houthi rebels launched missile and drone attacks which targeted oil facilities belonging to Saudi energy giant Aramco.Last September, similar attacks on Aramco installations caused massive destruction, temporarily halving the kingdom's crude oil output and wreaking havoc on global oil markets.

Motor Oil Hellas, owner of Greece's second-largest oil refinery and network of gas stations, has longstanding deals with Aramco.

The Saudi oil firm, which boasts one of the world's largest crude reserves, purchased 50 percent of shares in Motor Oil in 1995, which the latter bought back in 2005, according to the company's website.

In May last year, Abdulaziz al-Judaimi, Aramco's senior vice-president for downstream, told Reuters that the company would continue to invest in Greece, as part of its planned expansion into Southern Europe.

Discussion on Athen's plan to send missiles into the kingdom had begun in October, according to the government spokesman who made the Tuesday announcement."The deployment contributes to energy security, promotes our country as a factor of regional stability and strengthens our ties to Saudi Arabia," Petsas saidWhile he did clarify the date for the deployment, earlier this week he said that "around 130" Greek military personnel would accompany the missiles earlier, according to domestic news sources.The spokesman's announcment was condemned by Greek opposition parties as amounting to an act of military "adventurism".A day before, Greek Prime Minister Kyriakos met with the Saudi government in Riyadh for investment talks.Agencies contributed to this report.