The leaders of Germany and France vowed to protect the European single currency at all costs on Friday, as the clouds of the eurozone debt crisis seemed darkening fast over the past week.

After a telephone talk, German Chancellor Angela Merkel and French President Francois Hollande issued a brief but determined joint statement, saying that the two countries, usually seen as twin engines of Europe, "are deeply committed to the integrity of the eurozone" and would "do everything to protect the eurozone."

The two leaders called on all member states and European institutions to "meet their obligations, and their own area of expertise."

They urged that the decisions made in June's European Union (EU) summit must be "implemented quickly", referring the hard-earned agreements on allowing the eurozone's rescue funds to bailout banks directly once a European bank supervision authority is in place and easing certain conditions imposed on countries which apply for help, like Greece, Ireland and Portugal.

Merkel and Hollander's tones were similar to that of another influential figure in the battle with the long-lasting debt crisis -- Mario Draghi, head of the European Central Bank (ECB).

The bank chief pledged on Thursday in an investment conference in London that the ECB "is ready to do whatever it takes to preserve the euro" within the mandate.

He then added that "to the extent that the size of the sovereign premia (borrowing costs) hampers the functioning of the monetary policy transmission channels, they come within our mandate."

Analysts interpreted these words as evidence that the central bank would begin to buy bonds of debt-laden countries like Spain and Italy as an effort of keeping those struggling economies accessible to markets.

Over the past week, worries on the escalation of the debt crisis were intensifying fast, as Spain, Europe's fourth economy, faced unsustainable borrowing costs for several consecutive days, and Greece, which has been sinking in the crisis for more than two years, would run out of money again but could not secure the next emergency funds for sure.

With Spian's 10-year bond yields soaring to 7.6 percent earlier this week, which was well above the threshold of seven percent seen as unsustainable, the euro currency hit its recorded low against the dollar in two years, raising fears that Spain would be forced to seek a full state bailout and the debt crisis would deepen to a new level.

Although Merkel and Hollande, as well as Draghi, came up with no concrete plans in their statements, worldwide investors gave warm responses immediately.

On Friday, main stocks across Europe jumped considerably following the German-French statement. The borrowing rates of 10-year bonds of Spain and Italy have retreated to below seven percent.