BRUSSELS -- Ukraine maintained its appeal for Western countries to provide it with fighter jets Tuesday, but the United States and its NATO allies and partners voiced more concern about Kyiv's needs for large amounts of ammunition as the war with Russia approached its one-year anniversary.

Ahead of the meeting of the Ukraine contact group at NATO headquarters, Ukraine made its requirements clear. Defense Minister Oleksiy Reznikov, when asked what military aid his country is seeking now, showed reporters an image of a fighter jet.

Questioned about where he hoped they might come from, Reznikov said only: "From the sky."

What NATO allies have on their mind, though, is how to keep up a steady supply of ammunition to Ukraine without depleting their own stockpiles.

According to some estimates, Ukraine is firing up to 6,000-7,000 artillery shells each day, around a third of the daily amount that Russia is using.

Moscow's forces have been pressing in the east of Ukraine while bolstering their defensive lines in the south. The war has been largely static during the winter months, though both sides are expected to launch offensives when the weather improves.

German Defence Minister Boris Pistorius said that finding ammunition and air defences is "much more important at the moment than the discussion about fighter jets."

Pistorius told reporters that getting pilots up to speed on new aircraft and "training just to fly them takes several months, never mind teaching the abilities needed to deploy the weapons systems."

He said Ukraine's partners "should focus on what is now at centre stage, particularly in view of a Russian offensive that is apparently taking place."

NATO Secretary-General Jens Stoltenberg on Monday urged Ukraine's Western allies to step up their military support.

Asked when he expects Russia's so-called spring offensive to begin, Stoltenberg said that "the reality is that we have seen the start already."

"For me, this just highlights the importance of timing. It's urgent to provide Ukraine with more weapons," he told reporters in Brussels. Stoltenberg said that NATO sees "no sign whatsoever that President Putin is preparing for peace" and that arming Ukraine more quickly could save lives by bringing a quicker end to the conflict.