Many G20 Nations Support Bank Tax: France's Lagarde

Many of the G20 nations are supportive of a tax on banks and details of the levy should be hammered out over the next few weeks despite growing doubts over the prospects for a multinational agreement, French Finance Minister Christine Lagarde told CNBC Monday.

"There were many, many nations around the table today that were supportive of the taxation on banks," Lagarde said after attending the G20 meeting in Busan in the Republic of Korea.

"The group was encouraged to work on the principles that would be used to levy banks and this is work that is going to be done in the next few weeks," she added.

- Watch the full interview with Christine Lagarde above.

European Single Market Commissioner Michel Barnier unveiled plans for the bank levy at the end of May. But the plans were dropped from the Group's official communiqué in the face of widespread opposition, the Financial Times reported Monday.

UK Finance Minister George Osborne is reportedly pressing on with UK plans to tax banks and could unveil unilateral action at the next UK budget, according to the FT.

"Some of the steam has gone out of" the push for a united global financial regulation, Roger McCormick, author of 'Legal Risk in Financial Markets,' told CNBC Monday.

Aside from the potential bank tax, the G20 meeting of finance ministers discussed the best way to cut the deficits of the most indebted countries while maintaining economic growth, Lagarde said.

Lagarde also said that the recent investor concern over the debt situation in Hungary may be overblown and not based on the most relevant economic data.

"The authorities that have access to the numbers are not exactly on the same page as the political leaders at the moment," Lagarde said when discussing Hungary.

"We need a little bit of calm, serenity to go into the numbers and figure out what is real from what is actually part of the political messages," she said.