China is stepping up its role as the lender of last resort tosome of the world's most financially strapped countries.

Chinese officials signaled Saturday that they are willing toexpand a US$24 billion currency swap program to help Russia weatherthe worst economic crisis since the 1998 default. China hasprovided $2.3 billion in funds to Argentina since October as partof a currency swap, and last month it lent $4 billion to Venezuela,whose reserves cover just two years of debt payments.

By lending to nations shut out of overseas capital markets,Chinese President Xi Jinping is bolstering the country's influencein the global economy and cutting into the International MonetaryFund's (IMF's) status as the go-to financier for governments in financial distress.While the IMF tends to demand reforms aimed at stabilizing acountry's economy in exchange for loans, analysts speculate thatChina's terms are more focused on securing its interests in theresource-rich countries.

“It's always good to have IOUs in the back of yourpocket,” Morten Bugge, the chief investment officer at Kolding,Denmark-based Global Evolution A/S who helps manage about $2billion of emerging-market debt, said by phone. “These are China'sfellow friends and comrades, and to secure long-term energy couldbe one of the motivations.”

The ruble jumped 4.9 percent, to 55.8 per dollar, in Moscow onMonday after Hong Kong-based Phoenix TV cited China's CommerceMinister Gao Hucheng as saying that expanding the currency swapbetween the two nations would help Russia.

The ruble has gained 10 percent over the past two days, paringa selloff that's made it the world's worst performing currencyover the past six months.

Unlike Ukraine, where the pro-West government received a $17billion IMF-led bailout this year, Russia, Argentina, and Venezuelaare often at odds with the U.S. and its allies, essentially keepingthem out of the reach of the Washington-based institution. At $3.89trillion, China holds the world's largest foreign-exchangereserves, allowing it to fill the void.

China and Russia signed a three-year currency-swap line of 150billion yuan ($24 billion) in October, a contract that allowsRussia to borrow the yuan and lend the ruble. While the offer won'trelieve the main sources of pressure on the ruble—which has lost 41percent this year amid plunging oil prices and sanctions linked toRussia's annexation of Crimea—it could bolster investors'confidence in the country and help stem capital outflows.

Argentina Reserves

Two phone calls to China's central bank seeking comment on theterms of its currency swaps weren't returned. Russia isn't in talkswith China about any financial aid, Dmitry Peskov, a spokesman forPresident Vladimir Putin, said on Dec. 20.

Funding from China has helped raise Argentina's foreign reservesto a 13-month high of $30.9 billion, a boost for a country that hasbeen kept out of international capital markets since defaulting onforeign obligations in 2001.

Argentina received $1 billion worth of yuan earlier this monthas part of the three-year currency-swap agreement with China, acentral bank official in the South American country, who asked notto be identified because he isn't authorized to speak publicly,said Dec. 11. That extended the funds transfered to Argentina to$2.3 billion since October. The swap is for a maximum of $11billion over three years.

In Venezuela, President Nicolas Maduro last month added $4billion he borrowed from China to the country's reserves after theyfell to an 11-year low. The country now has about $21 billion inits coffers, equal to the amount of debt it has coming due in 2015and 2016.

Venezuela, which was already plagued by shortages of everythingfrom toilet paper to toothpaste, is also suffering from the drop inoil, its biggest export. Traders are betting that there's an 89percent probability that Venezuela won't be able to make good onits debts over the next five years, according to credit-defaultswaps data compiled by Bloomberg.

“I don't think this is a broad policy to support any countrythat asks for Chinese help,” Steffen Reichold, an economist atStone Harbor Investment Partners in New York, said in an email.“Several countries are currently in a tight spot and the Chineseare offering to help. That buys them some goodwill and influence,and promotes the use of the yuan.”

U.K., Australia

The People's Bank of China (PBOC) has signed currency-swapagreements with 28 other central banks around the world, includingthose in the U.K. and Australia, makingthe yuan an alternative to the dollar for global trade andfinance.

By promoting the use of its currency, China acts in its owninterests as it challenges the dominance of the U.S. in the globaleconomy.

Two months after Russia annexed Crimea in March, China signed athree-decade, $400 billion deal to buy Russian gas. Oil importsfrom Russia hit an all-time high in November, according to China'sGeneral Administration of Customs. While the ruble's depreciationaffected Chinese exports to Russia and made it difficult for thetwo countries to implement joint projects, the challenges shouldn'tbe exaggerated, according to a commentary published in the officialPeople's Daily newspaper today.

China has made $47 billion in loans to Venezuela since 2007,making it the country's largest creditor, according to EurasiaGroup, a political consulting firm. Venezuela, which holds theworld's largest oil reserves, repays the loans by shipping crude toChina.

In July, Xi signed trade and investment agreements for at least$7.5 billion in Argentina, cementing China's ties to the world'sthird largest soybean producer.

“China is playing an increasingly more important role and iswilling to engage,” Michael Ganske, who oversees $8 billion as thehead of emerging markets at Rogge Global Partners Plc, said bye-mail from London. “There is geo-strategic importance connectedwith” the funding deals, he said.

–With assistance from Katia Porzecanski in New York, VernonWessels in Johannesburg and Fion Li in Hong Kong.