Chavez said on Thursday: "We would like to thank you for delivering us from a blockade. We were almost disarmed."
Neither Chavez nor Vladimir Putin, the Russian president, gave details about any new deals signed on Thursday, but Russia's defence minister said last week that Moscow had agreed to sell the oil-rich South American nation about 30 Su-30 fighter jets and 30 military helicopters.
Putin said on Thursday that the two countries would prove "reliable partners" and - in comments clearly aimed at Washington - said their cooperation should not be viewed as being "aimed against any third country".
Chavez spoke of the "astonishing progress in military-technical cooperation" and said the fighter jets were critical because Venezuela had been unable to purchase replacement parts for its aging fleet of US-made F-16s.
The US announced a ban on US arms sales to Venezuela in May.
Chavez also thanked Russia for supporting Venezuela's push for a non-permanent UN security council seat, which the US is trying to block.
The US said on Tuesday that the arms sales did not help regional stability and urged Russia to reconsider the contracts.
Pavel Felgenhauer, a Moscow-based defence analyst, said: "Chavez wants to thumb his nose at the US, and the Russians are delighted to get his money."
Chavez arrived in Qatar on Friday and will also be visiting Iran. He described the region as "a zone once again lashed by the winds of war, a product...of the terrible tensions unleashed from Washington, the empire's attempt to dominate this planet.
"The US empire is the greatest threat the world faces today - irrational, blind, a clumsy giant, that doesn't understand life, that doesn't understand the world, that doesn't understand the rights of human beings."