The E.U. will keep letting in Ukrainian grains without tariffs.

BRUSSELS — Ukraine’s grains will continue to enter the European Union tariff-free for another year despite protests from neighbors such as Poland, which have seen their own farmers hurt by the influx of cheaper foodstuffs.

European Union ambassadors meeting in Brussels on Friday agreed to extend the tariff-free access that was put in place a year ago, but with some concessions for Ukraine’s E.U. neighbors affected by the glut of grain. The agreement was announced by Sweden, which is currently chairing the meetings. The European Parliament is set to give formal approval next month.

The lifting of E.U. tariffs was originally conceived as an emergency measure to create cheap, secure land routes to let vital supplies of grains out of Ukraine and alleviate a global food crisis prompted in part by Russia’s blockage of Ukrainian ports on the Black Sea.

But the policy, however well-meaning, backfired for Ukraine’s nearest E.U. neighbors. Tons of Ukrainian grains, significantly cheaper than their E.U. equivalents, flooded neighboring markets and, instead of traveling onward, were stockpiled in warehouses, causing prices in those nations to collapse.

The pain was felt instantly in Poland and other countries, where governments that have supported Ukraine faced protests from farmers, an important political constituency. In recent weeks, Bulgaria, Hungary, Poland and Slovakia enacted unilateral bans on Ukrainian food imports in an effort to contain the problem, to the consternation of officials in Kyiv and Brussels.

The grain glut in Eastern Europe continued even after the United Nations and Turkey eventually brokered a deal with Ukraine and Russia that allows vessels to transport grains out of Ukrainian ports under close supervision.

On Friday, the four countries that had enacted bans on Ukrainian grain, and Romania, secured several concessions from the European Union in order to agree to the extension of the tariff-free policy, E.U. diplomats familiar with the talks said after a meeting of ambassadors in Brussels. The E.U. trade commissioner, Valdis Dombrovskis, later confirmed on Twitter that Bulgaria, Hungary, Poland, Romania and Slovakia had agreed in principle to once again allow Ukrainian food products to pass through their territories.

Under the agreement, the diplomats said, certain types of Ukrainian grains — among them wheat and sunflower seeds — will only be permitted to transit through those nations on their way to other destinations. Officials hope that not allowing the sale of the grains will soften the effects on farmers in Ukraine’s neighboring states.

The countries will also receive 100 million euros ($110 million) from an E.U. emergency fund normally reserved to compensate farmers in case of natural disasters.

Details of the exemptions are being finalized and are likely to be adopted in coming days, E.U. diplomats and officials said.