The Spanish government has entered talks with Panama in the hope of easing a row over the expansion of the Panama Canal.
The group carrying out the work is lead by Sacyr, a Spanish company.
Work began in 2009, but has overshot its budget by a whopping $1.6bn (£1bn).
Nevertheless, the group has threatened to stop work until it receives the money. On 30 December it issued a 21 day deadline to the Panama Canal Authority to pay. The authority hinted that it could find others to finish the work.
Other companies in the group are from Italy, Belgium and Panama.
Panama’s president Ricardo Martinelli accused the Spanish and Italian companies of 'great irresponsibility' and endangering the massive project. He said: "I will go to Spain and Italy to demand these governments take moral responsibility."
But instead Spain’s public works minister will go to Panama along with Sacyr’s chairman to negotiate a solution.
Spain's ambassador to Panama, Jose Silva, noted that all stand to lose out if the contract fell through.
The works constitute building a third lock for larger ships carrying 12,000 containers to use. Presently, the top load through the Canal is 5,000.
Construction is due to be completed in June 2015, nine months behind schedule. The overall cost of the project now expected to be $5.2bn.
The Panama Canal handles 5% of the world's maritime trade.
