European Union countries are hitting some hurdles as they seek to agree on a fifth round of sanctions on Russia, with several countries saying the package is being watered down too much, according to people familiar with the matter.

EU ambassadors met Thursday morning with the aim of approving the package, which contains a coal embargo. But Poland is resisting a change in the draft sanctions plan, sought by Germany, that extends the phase-in period for the ban by a month to four months, the people said. The EU meetings are set to resume Thursday evening with the aim of finalizing the package.

Poland also wants to remove all remaining exemptions to the already existing ban on the sale of weapons, as well as military-related technologies and components, to Russia. The list of exemptions to the newly proposed sanctions has been growing during this week’s deliberations, especially on restrictions aimed at hitting Russian trucks and ships, one of the people said. Poland isn’t alone in opposing the exemptions, the people added.

Anger over reported atrocities by retreating Russian soldiers in Ukraine has fueled a push for a more punishing round of sanctions, but it’s also exposed deep fissures in the EU over how far countries are willing to go.

It’s also prompted growing complaints from Ukraine, which says the EU waited until reports of massacres of civilians, like the recent reports from the town of Bucha, before taking significant new steps.

“How many Buchas have to take place for you to impose the sanctions?” Ukrainian Foreign Minister Dmytro Kuleba told reporters in Brussels after meeting with NATO foreign ministers. “How many children, women, men have to die, innocent lives have to be lost for you to understand that you cannot allow sanctions fatigue as we cannot allow fighting fatigue?

Some of the exemptions on ships, for example, have been pushed by Greece, Malta and Cyprus, one of the people said.

Several countries have demanded restrictions on imports on Russian oil, which European Commission President Ursula von der Leyen said the bloc will discuss in the coming days. But Germany and Hungary have been opposed to such a step.

Adding additional pressure on EU governments, the European Parliament on Thursday called for an “immediate full embargo” on Russian imports of oil, coal, nuclear fuel and gas. Members of the assembly also endorsed complete abandoning of the Nord Stream pipelines carrying Russian gas to Germany as part of a non-binding resolution on Russia.