The European Union is urging Hungary not to block aid for Ukraine, as concerns rise over potential obstacles to European support for the war-torn nation, coinciding with doubts about U.S. backing due to opposition from Republicans in Congress.

On Monday, the EU Foreign Policy Chief, Josep Borrell, urged the bloc to enhance its support for Ukraine, as Hungary threatens to veto additional aid for the war-torn nation at this week’s summit. Concerns are rising that European support for Ukraine might face obstacles, coinciding with doubts about the backing from Kyiv’s key ally, the United States, due to opposition from Republicans in the US Congress.

“I hope that European unity will not be broken because this isn’t the moment to weaken our support for Ukraine,” said Borrell ahead of a meeting of the bloc’s foreign ministers.

The European Union’s 27 leaders will hold a crucial meeting on Thursday, during which Hungary’s Prime Minister Viktor Orban—Russia’s closest friend in the bloc—is threatening to block billions in aid and delay EU membership talks for Kyiv.

Ukraine’s Foreign Minister warned European Union leaders on Monday that if they fail to agree to open membership talks with Kyiv at their summit this week, it will have “devastating consequences.”

“I cannot imagine,” Dmytro Kuleba told reporters in Brussels, “I don’t even want to talk about the devastating consequences that will occur if the Council fails to make this decision.”

Finland’s Foreign Minister Elina Valtonen described Hungary’s position as “very, very deplorable.” She emphasized the importance of continuing to aid Ukraine for as long as necessary, highlighting its significance not only for Ukraine but also for the EU.

European diplomats believe that Orban is delaying support for Ukraine to pressure Brussels into releasing billions of euros of EU support to Budapest, frozen over a rule-of-law dispute.

Latvian Foreign Minister Krisjanis Karins labeled Hungary’s position a “challenge” and expressed confidence in the EU’s ability to overcome such challenges, citing past experiences.

At the summit this week, the EU aims to finalize agreements, including providing Ukraine with an additional 50 billion euros in financial aid, increasing a weapons fund for Kyiv by five billion euros, and opening talks for Ukraine to join the bloc next year.

Miroslava Salazar, with AFP