By LOLITA C. BALDOR and MATTHEW LEE

WASHINGTON — The Pentagon will send Ukraine at least $275 million in new weapons, U.S. officials said Tuesday, as the Biden administration races to do everything it can to help Kyiv fight against Russia in the remaining two months before President-elect Donald Trump takes office.

The latest tranche of weapons comes as concerns grow over an escalation in the conflict, with both sides scrambling to gain any advantage they could exploit if Trump demands a quick end to the war – as he has committed to doing so.

This week, in quick succession, President Joe Biden gave Ukraine the authority to fire longer range missiles deeper into Russia, then Russian President Vladimir Putin officially lowered the threshold for use of nuclear weapons.

U.S. officials say Russia’s change in nuclear doctrine was expected, but Moscow warns Ukraine’s new reliance on nuclear doctrine Army tactical missile system, known as ATACMSTuesday in Russia, could trigger a strong reaction.

A U.S. official said the United States saw no indication that Russia was preparing to use a nuclear weapon in Ukraine. The U.S. officials spoke on condition of anonymity because the aid package has not yet been made public.

Asked Tuesday whether a Ukrainian attack with longer-range U.S. missiles could potentially trigger the use of nuclear weapons, Kremlin spokesman Dmitry Peskov said yes. He highlighted the provision of the doctrine that leaves the door open after a conventional strike that raises critical threats to the “sovereignty and territorial integrity” of Russia and its ally Belarus.

A U.S. official said Ukraine fired about eight ATACM missiles at Russia on Tuesday, and only two were intercepted. The official said the United States was still assessing the damage, but that the missiles hit a munitions supply site in Karachev, Bryansk region.

Weapons in the new aid package for Ukraine include an injection of air defense, including High Mobility Artillery Rocket Systems (HIMARS), as well as 155mm and 105mm artillery shells, ammunition Javelin anti-armor rifles and other equipment and spare parts, U.S. officials said. say.

The weapons will be provided by presidential withdrawal authorityallowing the Pentagon to quickly pull supplies off its shelves and move them quickly to the Ukrainian front line.

Trump’s upcoming arrival at the White House has sparked a rush by the Biden administration to ensure that all Congress approved funding for Ukraine is delivered and that Kyiv is in a strong position as winter approaches.

The Biden administration is expected to spend $7.1 billion on weapons from the Pentagon’s stockpile to spend all of those funds before Trump is sworn in. This includes $4.3 billion from a the foreign aid bill passed by Congress earlier this year and $2.8 billion in savings are still expected thanks to the Pentagon’s recalculation of the value of the systems sent.

As part of a broader effort, the administration is also in the process of dispersing its share of a $50 billion loan to Ukrainebacked by frozen Russian assets, before Biden left the White House, according to two senior administration officials.

The officials, who were not authorized to comment publicly, said the United States and Ukraine were now in “advanced stages” in discussions over loan terms and were seeking to complete the process for part of $20 billion from the gigantic loan that the United States is backing. .

The goal is to achieve this before the end of the year, an official said.