As the U.S. expresses concern about Russian military activity near Ukraine’s border, a group of House Republicans is calling for President Joe Biden to deploy troops to the region.

Secretary of State Antony Blinken acknowledged “reports of unusual Russian military activity near Ukraine,” Fox News reported.

“We’re monitoring the region very closely,” Blinken said. “As we always do, we’ll continue to consult closely as well with allies and partners on the issue.

“And as we’ve made clear, any escalatory or aggressive actions would be of great concern to the United States.”

“Our concern is that Russia may make a serious mistake of attempting to rehash what it undertook back in 2014, when it amassed forces along the border, crossed into sovereign Ukrainian territory and did so claiming falsely that it was provoked,” Blinken said in a reference to Russia’s invasion of Crimea, CNN reported.

Republican members of the House Armed Services Committee sent a letter to Biden urging him to deploy troops to the region.

“With the recent massing of Russian forces on the Ukrainian border, we urge your administration to take immediate and swift action to provide support to Ukraine in the form of intelligence and weapons,” wrote Ohio Rep. Mike Turner, the top Republican on the Subcommittee on Strategic Forces. “We also urge your administration to deploy a U.S. military presence in the Black Sea to deter a Russian invasion.

“According to open-source reporting, Russia is once again massing a sizable military force of ground troops, armored vehicles, tanks, and artillery on Ukraine’s doorstep. Russia’s behavior is becoming more aggressive, and it has intensified rhetoric critical of Ukraine on topics ranging from Ukraine’s military modernization and military partnerships to Ukraine’s admission into NATO. Although Russia’s intentions are uncertain, the presence of Russia’s elite 1st Guard Tanks Army lends credibility to concerns that Russia is planning additional incursions into Ukraine territory. Your administration cannot ignore Russia’s continued threat to international law and Ukraine’s territorial sovereignty.

“We urge you to immediately consider an appropriate U.S. military presence and posture in the region and to initiate appropriate intelligence sharing activities between the U.S. and Ukraine to prevent the situation from escalating further.”

Meanwhile, Chairman of the Joint Chiefs of Staff General Mark Milley said last Wednesday that the U.S. is seeing a significant amount of Russian military movement along its border with Ukraine, but nothing that was “overtly aggressive,” Reuters reported.

“We’ve seen this before … What does this mean? We don’t know yet, too early to tell,”  he said.