EU's foreign policy chief Josep Borrell. Photo: EPA

European Union chief diplomat Josep Borrell believes that domestic political issues in the United States "fuel uncertainty" on its future support for Ukraine, as US Congress scrambles to adopt federal funding.

In a blog post following his visit to Ukraine, Mr Borrell recalls that he and his delegation learned of the passing of a bipartisan bill that did not include Ukraine support in Congress.

The bill extended temporary government funding for 45 days, giving the American lawmakers some time to negotiate long-term spending, bur resulted in House speaker Kevin McCarthy ousted following an outcry from far-right Republicans, who had accused him of colluding with the White House on Ukraine aid.

"Despite the strong engagement of the Biden administration, it fuels uncertainty on future US’ support to this country," the EU chief diplomat believes.

"In the short term, we couldn’t compensate for the lacking US support, and we hope that our friends and allies will quickly find ways of breaking the deadlock.

"For the future, this development increases EU’s responsibility to rise to the challenge launched by Vladimir Putin, a few kilometres from our borders, against our core democratic values and the international rules-based order to which the European project has always been closely linked since the beginning."

Mr Borrell also reiterated the EU’s support for the Ukrainian peace formula, stressing that the war against Ukraine should end on Kyiv’s terms.

"With our first of this kind EU foreign ministers’ meeting in Ukraine, we have sent a strong signal to Russia: we continue and will continue to fully support Ukraine’s fight for freedom and sovereignty," he stressed.