Qatari Foreign Minister Sheikh Mohammed bin Abdulrahman al-Thani also said there was no sign of a thaw in a Persian Gulf row over allegations by Saudi Arabia and some other Arab states that Qatar supports terrorism. Doha denies the charges.
"There is a discussion for procurement of various Russian equipment but there is no understanding as of yet as to this particular equipment (S-400)," Sheikh Mohammed told a joint news conference with Russia's Foreign Minister Sergei Lavrov, Reuters reported.
"With regards to Saudi or other countries it is none of their business, it's a sovereign decision by Qatar," he said, adding that a technical committee was studying the best options for the tiny but wealthy country's military.
The minister was responding to a question about a report last June by France’s Le Monde daily that Saudi King Salman had sent a letter to France's president expressing concern over talks between Doha and Moscow about the S-400 systems.
Sheikh Mohammed said discussions with Lavrov, who is in Doha on the first stop of a Persian Gulf tour, also covered Syria and Libya.
He reiterated that Doha was not yet ready to normalize ties with Syria. He also called for unity in Libya.