European Central Bank President Jean-Claude Trichet says he expects markets to gradually boost confidence in Greece following the government's austerity measures.

Greece's borrowing costs remain high despite the government's plan to cut its budget deficit and an agreement reached in Brussels last week to rescue the country if it finds itself unable to pay its debt or borrow on the market.

Trichet told reporters Wednesday he expects "the credibility of these measures will be progressively recognized by all market participants."

The spread between Greek 10-year bonds and equivalent German issues — considered a benchmark — climbed to 345 basis points on Wednesday before narrowing slightly to 335, up from the 306 basis points on Monday. That suggests market mistrust remains high.