This was the case despite US restrictions on countries allowed to compete for tenders, he said.
"The US decision does not concern all of the money which will be spent on the reconstruction of Iraq," Belka, a former Polish finance minister, told a news conference on Wednesday.
"It does not concern money which is at the disposal of Iraq's ministries, in the framework of the Iraqi state budget. It does not concern the money that comes from other countries, from international organisations, the World Bank or International Monetary Fund," he said in the Polish capital Warsaw.
"There is also in Iraq a large number of contracts which had already been paid or at least approved by the Iraqi state in the framework of the Oil for Food programme," he said.
On Tuesday, the United States sparked controversy when it announced barring companies from nations that refused to join the US-led occupation in Iraq, from competing for 26 prime contracts to rebuild the country.
The ban applies to firms from France, Germany, Russia, and other countries, while bids for $18.6 billion worth of contracts would be confined to those from its occupation partners, which include such countries as Britain and Estonia.
Limits on bidding for more than $18 billion worth of projects apply to countries such as France, Germany and Russia.
However, Belka said "countries excluded by the Pentagon are already present in Iraq. For example (the German group) Siemens is a subcontractor of a (winning) US company and of one of the first tenders."
Earlier this week the Pentagon said it had postponed until January a conference of bidders on billions of dollars on prime contracts for Iraq reconstruction projects.
The reason for the delay was to select a core group of bidders from thousands of companies that have expressed interest in the 26 prime contracts for reconstruction projects.