WASHINGTON — The Pentagon will send Ukraine at least $275 million in new weapons, including an undisclosed number of antipersonnel land mines, as the Biden administration rushes to do as much as it can to help Kyiv fight back against Russia before President-elect Donald Trump takes office. The latest tranche of weapons comes as worries grow about an escalation in the conflict, with both sides pushing to gain any advantage they can exploit if Trump demands a quick end to the war — as he has vowed to do. "We will continue to provide Ukraine the support it needs to succeed on the battlefield and prevail in its defense against Russia's aggression," Secretary of State Antony Blinken said in a statement.

In rapid succession this week, President Joe Biden gave Ukraine the authority to fire longer-range missiles deeper into Russia and said it would provide the antipersonnel land mines. Russian President Vladimir Putin also formally lowered the threshold for using nuclear weapons. U.

S. officials contend that Russia's change in nuclear doctrine was expected, but Moscow is warning that Ukraine's new use of the Army Tactical Missile System, known as ATACMS, inside Russia on Tuesday could trigger a strong response. One American official said the U.

S. is seeing no indications that Russia is preparing to use a nuclear weapon in Ukraine. Asked Tuesday if a Ukrainian attack with longer-range U.

S. missiles could potentially trigger use of nuclear weapons, Kremlin spokesman Dmitry Peskov an.