The U.S. State Department says it has approved an export license for Ukraine to buy certain types of light weapons and small arms from U.S. manufacturers.
Spokeswoman Heather Nauert said on December 20 that Congress was notified of the decision on December 13.
The license covers weapons in categories such as semiautomatic and automatic firearms up to .50 caliber weapons, combat shotguns, silencers, military scopes, flash suppressors, and parts.
It does not allow the sale of heavier weapons, such as Javelin antitank missiles, that Ukraine has urged Washington to provide in order to strengthen its capabilities against the Russia-backed separatists it is fighting in the Donetsk and Luhansk regions.
There are conflicting reports about the significance of the development.
An article in The Washington Post described the State Department decision as approval of "the first-ever U.S. commercial sale of lethal defensive weapons to Ukraine" and a "clear break" with past policy.
But the State Department and other media reports contradicted that.
"Under the previous two administrations, the U.S. government has approved export licenses to Ukraine, so this is nothing new," Nauert said.
According to Reuters, State Department records show that Ukraine has bought small amounts of light weapons and small arms for several years, both before and after Russia's seizure of Ukraine's Crimea region in March 2014.
U.S. exporters can apply for direct commercial-sales licenses, which are reviewed by the State Department on a case-by-case basis, Nauert said.
Nauert said that the U.S. government has not directly provided lethal defensive equipment to Ukraine, but has not ruled out doing so.
The top U.S. military commander, General Joseph Dunford, said earlier this year that he recommended that the United States provide lethal defensive weapons to Ukraine to help the country "protect [its] sovereignty."
Dunford, chairman of the Joint Chiefs of Staff, said in testimony before the Senate Armed Services Committee on September 26 that a proposal to provide lethal aid to Ukraine was awaiting a decision from the White House.
Ukrainian authorities have asked in particular for portable Javelin missiles, which they say would help soldiers in eastern Ukraine fend off attacks from tanks and self-propelled artillery.
Last month, ABC News reported that senior aides would present U.S. President Donald Trump with a $47 million plan to finance and sell high-tech defensive weapons to Ukraine.
Citing a State Department source, ABC News on November 18 said the proposed package included Javelins.
The war between Kyiv's forces and the Russia-backed separatists has killed more than 10,300 people since April 2014.
The U.S. envoy for peace efforts in eastern Ukraine, Kurt Volker, said on December 19 that 2017 had been "the most violent year" of the conflict and warned that hostilities were on the rise.
European Union foreign-policy chief Federica Mogherini said on December 20 that the humanitarian and security situation in the conflict zone has "deteriorated abruptly."
With reporting by The Washington Post, Reuters, CNN, ABC, and The Hill