Ukraine is at a "critical moment" in its war with Russia and urgently needs more Western support, U.S. Secretary of State Antony Blinken said on Tuesday, bemoaning the stalemate in Congress over a multi-billion dollar military package for Kyiv.

"It is absolutely essential to get Ukrainians what they continue to need to defend themselves, particularly when it comes to munitions and air defences," Blinken told reporters during a visit to France.

"It's another reason why the supplementary budget request that President (Joe) Biden has made to (the U.S.) Congress must be fulfilled as quickly as possible."

Biden has urged the Republican-controlled U.S. House of Representatives to endorse the military and financial aid package, but House Speaker Mike Johnson has held up the matter for months, citing domestic priorities.

Ukrainian President Volodymyr Zelenskiy has said that if Ukraine does not get the aid, his forces will have to retreat "in small steps".

Blinken and French Defence Minister Sebastien Lecornu had earlier visited a factory where arms producer Nexter produces Caesar howitzer cannons. Lecornu said Nexter was working to produce 12 Caesar cannons a month compared to six at the moment.

French President Emmanuel Macron has in recent weeks adopted a more hawkish stance towards Russia, amid fears that Ukraine is losing ground in the war, notably as U.S. support wanes.

PRESSURE IN MIDDLE EAST

Events in the Middle East are likely to take centre stage during Blinken's visit.

He arrived in Paris for talks with senior officials including Macron just hours after a Washington-based NGO World Central Kitchen was struck by an Israeli airstrike in central Gaza, adding pressure on Washington to toughen its stance in the war between Israel and Hamas.

Suspected Israeli warplanes bombed Iran's embassy in Syria on Monday in a strike that Iran said killed seven of its military advisers, including three senior commanders, marking a major escalation in Israel's war with its regional adversaries.

Blinken will hold talks with French Foreign Minister Stephane Sejourne before meeting Macron. French diplomats say they want to step up efforts at the United Nations to build an international consensus for a ceasefire in Gaza.

"You can sense the Americans are a bit uncomfortable at the moment," said one diplomat, pointing to the contrast between Washington's humanitarian efforts in Gaza and its ongoing supply of weapons to Israel.

On Monday, France proposed a draft U.N. Security Council resolution that seeks options for possible U.N. monitoring of a ceasefire in the Gaza Strip and proposals to help the Palestinian Authority assume responsibilities.

The United States, which last blocked a French-backed resolution in 1997, abstained from a vote last month to allow the 15-member council to demand an immediate ceasefire for the Muslim fasting month of Ramadan, which ends next week.

(Writing by John Irish; Editing by Ingrid Melander and Gareth Jones)