Owners of Argentine bonds marked in euros will appeal against a court order that has blocked payments to the country's creditors.
Lawyers for the group of bond holders have told a court in New York they want to see overturned a judgement last month that froze all payments.
That decision helped push Argentina into default.
Holders of bonds marked in euros argue that their bonds should be dealt with under English and Welsh law.
Last month Argentina defaulted on its debt - for the second time in 13 years - after last-minute talks in New York with a group of bond-holders ended in failure.
So-called "vulture fund" investors were demanding a full pay-out of $1.3bn (£766m) on bonds they hold.
Those investors, also known as "hold-outs", are US hedge funds that bought debt cheaply after Argentina's economic crisis.
They never agreed to the restructuring accepted by the majority of bond-holders.
Argentina said it could not afford to pay them, and accused them of using its debt problems to make a big profit.
The country was prepared to pay bond holders who had to agreed to restructure their debt but not the hedge funds. But the court ruled that all creditors would have to be paid simultaneously.
Owners of the eurobonds argue that their bonds are not covered by US rulings and that they should be paid.