U.S. President Joe Biden approved an additional $675 million weapons package for Ukraine, Defense Secretary Lloyd Austin said on Thursday, as U.S.-allied ministers met to discuss how to give Kyiv long-term support in countering Russia's invasion.

The six-month-old conflict, which has killed thousands and reduced Ukrainian cities to rubble, has settled into a war of attrition fought primarily in eastern and southern Ukraine.

Austin, who was speaking at the start of a meeting of dozens of defense ministers at Ramstein air base in Germany, said the gathering would discuss how countries can work together to train Ukrainian forces and improve their defenses.

"This contact group needs to position itself to sustain Ukraine's brave defenders for the long haul," Austin said, referring to the meeting. "That means a continued and determined flow of capability now."

The latest U.S. package will include more ammunitions, humvees and anti-tank systems.

Washington has already provided more than $10 billion in military assistance to President Volodymyr Zelenskiy's government since Russian troops invaded on Feb. 24.

Separately, U.S. Secretary of State Antony Blinken will announce $2 billion in new U.S. military financing to Ukraine and 18 other countries at risk of future Russian aggression, a senior State Department official said.

Ukraine has been carrying out a counter offensive in the south, though details about it are sparse. Western military analysts believe Russia may have left itself exposed in other areas as it rushed to reinforce the south.

U.S. officials say they are aware that Russia is hoping that Western unity will be tested in the coming months with European countries squeezed by reduced supplies of Russian natural gas and the upcoming November mid-term elections in the United States.

Control of the U.S. Congress is at stake in November's midterm elections, along with Biden's remaining policy agenda. Those advocating for Ukraine are concerned that Washington's attention may turn to domestic issues as November nears and voters may be more driven by issues closer to home like the economy.

Earlier this month, the White House said Biden would request $11.7 billion in emergency funding from Congress to provide weapons and budget support to Ukraine.

"Our support for Ukraine's bedrock right to defend itself doesn't waver based on any given clash," Austin said. "We must evolve as the fight evolves."

Russian President Vladimir Putin calls the campaign a "special operation" to demilitarize Ukraine, while Kyiv accuses Moscow of an imperial-style land-grab to retake a pro-Western neighbor that shook off Russian domination when the Soviet Union broke up in 1991.