Commission President Jose Manuel Barroso said he had written to heads of state to stress the "very, very serious fact that if we do not have a solution there will be a problem of legal certainty and that will be detrimental to their interests".

The European Union and the African, Caribbean and Pacific (ACP) group of states are locked in talks for new trade deals.

Brussels says the Economic Partnership Agreements will help development but some ACP countries fear they will open their economies to too much competition.

The new deals would replace preferential trade arrangements which were ruled illegal by the World Trade Organisation.

A WTO waiver permitting those long-standing arrangements is due to expire on January 1 and the EU has insisted it will not seek a new one, raising the prospect of higher EU tariffs for exports from ACP countries that have not signed new deals by then.

"I believe we have no alternative to finding a WTO compliant agreement in coming days to avoid any disruption of ACP trade at the beginning of 2008," Barroso told reporters.

Aid campaigners have accused the EU of strong-arming countries into signing the deals.

EU governments agreed on Tuesday that the bloc could settle for interim trade deals with some or all of the ACP countries.

After five years of negotiations, Brussels now aims to secure "stepping stone" deals covering trade in goods, and possibly with only some countries in each of the regions.

The interim deals would pave the way for talks on more sensitive areas such as services and investment rules in 2008.

An EU official said on Thursday that interim deals could be initialled this week with three of six ACP regions -- eastern and southern Africa (ESA) including countries such as Kenya and Uganda, southern Africa including South Africa, and the Pacific.

EU Trade Commissioner Peter Mandelson was more cautious. "It remains to be seen," he told Reuters.

At a meeting of national-level development ministers, the Commission proposed measures to reassure France and Spain that their banana growers, in the Caribbean and the Canary Islands, would be protected against surges of imports from ACP countries.

Under the plan, the Commission would launch an investigation possibly leading to safeguard measures to slow ACP banana imports if they increased by 25 percent or more compared with the average of the previous three years.

Sweden, the Netherlands and Britain, which traditionally support free trade, opposed safeguards for anything but rice and sugar, barriers to which are being removed gradually.