Qatar will invest $500m in Lebanese government US dollar bonds to support Lebanon's economy, the Qatari Ministry of Foreign Affairs has said.

Lebanon has the world's third highest public debt compared with the gross domestic product (GDP) and stagnant growth. Comments from its finance minister 10 days ago about Lebanon's public debt triggered concerns it might be restructured, leading to a sell-off in the country's dollar-denominated sovereign bonds.

The decision to invest came after Qatar's Emir Sheikh Tamim bin Hamad Al Thani made a brief visit to the Arab economic summit in the Lebanese capital Beirut on Sunday, during which he met President Michel Aoun.

Qatar's Foreign Minister Mohammed bin Abdulrahman Al Thani stressed on Monday that his country has always been committed to supporting Lebanese people in light of the challenges they face, and the move stems from the "profound fraternal ties between the two brotherly countries".

"We wish stability and prosperity for the Lebanese Republic and the Lebanese people, and that the Lebanese economy will recover," the foreign minister said in a statement to Qatar News Agency (QNA).

"The region needs a strong and prosperous Lebanon."