Qatar said on Monday it plans to buy $500 million of Lebanese government bonds to help support one of the world’s most indebted countries. Eurobonds rallied by the most since September.

Lebanon’s struggling economy needs a cash infusion to reassure bond holders still reeling from mixed remarks by officials about the possibility of debt restructuring this month.

Finance Minister Ali Hasan Khalil roiled bond markets when he told a newspaper the country may restructure its debt as part of a plan to repair public finances battered by sluggish economic growth, a political impasse that has left it without a functioning government for months and the war in neighboring Syria. He later denied the plans and officials got together to reassure investors the country would honor its obligations on time.

The Qatari announcement came a day after Sheikh Tamim bin Hamad Al Thani’s appearance at an Arab economic summit prompted speculation that the wealthy Gulf gas exporter planned to make a $1 billion deposit in Lebanon’s central bank. That investment was never confirmed.

The yield on Lebanon’s dollar bonds due 2028 plummeted 40 basis points to 10.9 percent, according to prices compiled by Bloomberg. It’s the lowest since Jan. 9, a day before confusion over Lebanon’s debt plans unnerved markets.

“It’s a show of support but it won’t be enough to address the challenges the country faces,’’ said Mohieddine Kronfol, Franklin Templeton Investments’ chief investment officer for global sukuk and Middle East and North Africa fixed income. “The top priority has to be restoring and maintaining confidence in the Lebanese banking system and that can only happen with a government in place and a credible structural reform agenda.’’

Lebanon has agreed to reduce its deficit by a percentage point annually for five years as one of the main conditions to unlock $11 billion in loans and grants offered at a 2018 donor conference. Public debt, estimated at over 160 percent of gross domestic product this year, is projected to rise to near 180 percent by 2023, second only to Japan’s, the International Monetary Fund says. Its “debt affordability” is the weakest of all the sovereigns rated by Moody’s Investors Service.

The Qatari gesture would “reinforce the Lebanese central bank’s foreign assets and the reserves adequacy ratio, in addition to the favorable effects it would have on the balance of payments,” said Marwan Barakat, chief economist at Bank Audi, Lebanon’s biggest lender.

The Qatari ruler’s first-ever visit to Lebanon on Sunday was to participate in the Arab economic summit snubbed by most other leaders. The energy-rich nation has faced a boycott since June 2017 by its larger neighbors Saudi Arabia and the United Arab Emirates, who accuse it of interfering in their internal affairs and getting too close to Iran. Qatar denies those allegations but its decision to buy Lebanese bonds will be watched closely by its rivals.

Sergey Dergachev, senior portfolio manager at Union Investment Privatfonds GmbH in Frankfurt, said Lebanon had become a proxy in the fight between Qatar and Saudi Arabia.

As the world’s biggest exporter of liquefied natural gas, Qatar often finds itself playing the role of benefactor, doling out cash and promises in a region riven by feuds. The emir met President Recep Tayyip Erdogan at the height of Turkey’s financial crisis last year and pledged to invest $15 billion in the country. In 2012, Qatar made a deposit at Egypt’s central bank. With the Muslim Brotherhood removed from office the following year, Egypt’s foreign policy changed and it welcomed multi-billion dollar inflows from Saudi Arabia and the UAE.

Qatar’s plan will give investors some assurance that there will be a buyer of last resort for Lebanese Eurobonds, said Richard Segal, senior analyst at Manulife Asset Management in London.

“There may be a bilateral diplomatic agenda in the background, or the investment could relate to the very high yield on the Eurobonds,” he said.