"It undermines the influence of the United States in the fund and in the global economy," Borg told the TT news agency.
The eurozone debt crisis was high on the agenda during a spring meeting of the world's most powerful finance ministers and central bank heads.
"The tougher discussions are focused on Europe and the uncertainty in the Spanish banking system," Borg said during a conference call with reporters in Sweden on Sunday.
On Friday, the G-20 group of countries pledged $430 billion to strengthen the IMF crisis fund, more than the $400 billion requested by IMF head Christine Lagarde.
While emerging economies such as Russia and China are among countries that contributed to the fund, the United States hasn't pledged any more commitments to the IMF.
The most generous of the crisis fund donors are among the eurozone countries which together have pledged $200 billion.
Sweden, meanwhile, has agreed to donate $10 billion.
"The Nordic and Baltic countries have had the strength to step forward in this situation. For a little country like Sweden, it's important to show that we're are a part of the global economy," said Borg.
"We have the muscle left to take certain measures. Sweden is held up as a role model."