WASHINGTON, Nov 10 - The Biden administration is stepping up pressure on Russia over a buildup of troops along its frontier with Ukraine, The Associated Press reported.

Secretary of State Antony Blinken told his Ukrainian counterpart Dmytro Kuleba in Washington on Wednesday that the U.S. commitment to Ukraine’s security and territorial integrity is “ironclad” and will not change. He said any Russian escalation along the border would be viewed with “grave concern.”

“We’re concerned by reports of unusual Russian military activity near Ukraine,” Blinken said at the conclusion of a U.S.-Ukraine strategic dialogue meeting. “Any escalatory or aggressive actions would be of grave concern to the United States.”

Blinken said the U.S. did not know Russia’s intentions but said Moscow’s “playbook” has been in the past to invent provocations along its border to justify military intervention. “We don’t have clarity into Moscow’s intentions, but we do know its playbook,” he said. “If there are any provocations that we’re seeing, they’re coming from Russia.”

Kuleba said the key to deterring Russian aggression is not only for Ukraine to remain strong but for its allies to speak out firmly in support of Kyiv.

“What is unfolding in Europe now is a very complicated thing with many elements to it,” the Ukrainian foreign minister said, noting cyberattacks, the spread of misinformation and disinformation aimed at destabilizing democracies, the use of migrant populations to foster unrest and the movement of troops. “In this complicated game, we have to remain vigilant, we have to be resilient.”

Earlier, the top U.S. diplomat for Europe told The Associated Press that senior Russian officials had been warned of potential consequences for any increased threat to Ukraine’s security.

Karen Donfried, assistant secretary of state for Europe and Eurasia, would not discuss specific consequences for Russia, but administration officials have in the past said boosting military support for Ukraine is one option. She also said the U.S. would continue to warn Russia against using energy exports as a political weapon against Europe generally and Ukraine specifically.

Donfried was part of a U.S. delegation led by CIA Director William Burns that visited Moscow last week and delivered that message personally to Kremlin officials. After leaving Moscow, Donfried traveled to Kyiv to brief Ukrainian officials on the meetings.

Ukraine’s Defense Ministry said last week that about 90,000 Russian troops are stationed not far from the border and in rebel-controlled areas in Ukraine’s east. It said specifically that units of the Russian 41st army have remained in Yelnya, about 160 miles (260 kilometers) north of the Ukrainian border.

In addition to amplifying U.S. concerns about the Russian troops, Blinken and Donfried said Washington, along with its European partners, is watching with trepidation to see if Moscow follows through on pledges to meet European demand for natural gas, particularly in the upcoming winter months.

“Russia can and should provide additional supplies through Ukraine, which has sufficient pipeline capacity and they don’t need Nord Stream 2 for that,” Donfried said. “And, if Russia fails to do that, obviously it’s going to hurt European energy security and bring into question what Russia’s motives are for withholding those supplies.” (ap/ez)