From Allies and Advisers, Pressure Grows on Biden to Allow Attacks on Russian Territory

President Biden is edging toward what may prove to be one of his most consequential decisions in the Ukraine war: whether to reverse his ban on shooting American weapons into Russian territory.

He has long resisted authorizing Ukraine to use U.S. weapons inside Russia because of concern it could escalate into a direct American confrontation with a nuclear-armed adversary.

Now, after months of complaints about the restrictions from Ukraine’s president, Volodymyr Zelensky, the White House has begun a formal — and apparently rapid — reassessment of whether to take the risk. Approving further uses of U.S. weapons would give Kyiv a way to conduct counterattacks on artillery and missile sites that now enjoy something of a safe haven just inside Russia.

On Wednesday, in Moldova, Secretary of State Antony J. Blinken became the first administration official to publicly leave open the possibility that the Biden administration might “adapt and adjust” its stance about attacking inside Russia with American weapons, based on changing battlefield conditions.

“We’re always making determinations about what’s necessary to make sure that Ukraine can effectively continue to defend itself,” Mr. Blinken said.

His statement was the latest amid a drumbeat of calls for a shift, from allies and from within Mr. Biden’s administration. Mr. Blinken, who returned from a sobering trip to Kyiv earlier this month, reported to the president that the Ukrainians might not be able to hold the territory between Kharkiv and the Russian border unless Mr. Biden reversed himself. That earlier warning was conveyed privately, in keeping with Mr. Biden’s deep aversion to letting debates among his inner circle leak out and create pressure on him to shift strategy.