Belt tightening in Europe will be «extremely painful» and could take up to 20 years, the chief economist of the International Monetary Fund (IMF) warned yesterday. Referring to highly indebted eurozone economies such as Greece, Olivier Blanchard said in an interview with Italy’s La Repubblica that «the adjustment is easier for countries that can devalue their currency. In countries that do not have this option, it is fair to say that the tightening will be extremely painful.» In the short term, he said, countries would have low growth rates and «sacrifices on salaries will be inevitable in order to regain competitiveness.» Finance officials from the European Commission, the European Central Bank and the IMF arrived in Athens yesterday at the start of a three-day trip to check on efforts to tame its rampant debt on the eve of a general strike against austerity measures. Meanwhile, Fitch Ratings yesterday lowered its issuer-default ratings on Greece’s four biggest banks, saying fiscal tightening from the Greek government will «have a significant effect on the real economy.» The ratings service cut the long-term IDRs on National Bank, Alpha Bank, EFG Eurobank and Piraeus Bank to BBB, the second-lowest investment grade rating, from BBB+, with a negative outlook. Fitch said Greek banks’ already-weakening asset quality and profitability «will come under further pressure» because of fiscal adjustments that «need to be made» by the Greek government. Those adjustments will affect loan demand and put additional pressure on asset quality, which could result in higher credit costs and ultimately weaker underlying probability, Fitch said. The banks’ profits also are likely to be affected by increased funding costs because uncertainties surrounding Greek public finances «have, to a large extent, constrained» their access to wholesale and interbank markets at reasonable prices, Fitch said.