By Steven Lee Myers and Steven Erlanger

New York Times News Service

MOSCOW — Even as Russia and Ukraine signaled a modest willingness to seek a diplomatic resolution to the widening crisis over Crimea on Saturday, there were new reports of Russian reinforcements there, and Russia raised the possibility of suspending inspections required under arms control treaties because of stepped-up operations by NATO.

“We are ready to continue a dialogue on the understanding that a dialogue should be honest and partner-like, without attempts to portray us as one of the parties in the conflict,” Russia’s foreign minister, Sergei Lavrov, said during an appearance with his counterpart from Tajikistan.

Hours after he spoke, however, Russia began moving new troops in unmarked uniforms in large trucks around Crimea, and a Ukrainian defense spokesman there told The Associated Press that witnesses had reported seeing amphibious military ships unloading about 200 military vehicles in eastern Crimea on Friday after apparently having crossed the Strait of Kerch, which separates Crimea from Russian territory.

The Ukrainian spokesman said that a convoy of about 60 military trucks was moving from Feodosiya toward an airfield near Simferopol, Crimea’s regional capital. A Ukrainian border patrol plane was also fired on near the boundary between Crimea and Russia, the Ukrainians said, but was not damaged.

In Moscow, an unidentified military official told Russian news agencies that Russia was considering suspending inspections of its nuclear arsenal required by the strategic arms reduction treaties, as well as other military cooperation agreements meant to build confidence and avoid international confrontations.

The official said the move was justified by “baseless threats” against Russia by the United States and NATO. A suspension of the inspections would undermine a pillar of international security and expand the confrontation beyond Ukraine itself.

Although President Barack Obama has made it clear that the United States does not want to escalate the Crimean crisis, the Pentagon stepped up training operations in Poland and sent fighter jets to patrol the skies over Lithuania, Latvia and Estonia, three former Soviet republics with sizable populations of ethnic Russians. Obama, who was spending the weekend in Florida, also held phone consultations about Ukraine with the French president and the British and Italian prime ministers, then had a conference call with the presidents of Estonia, Latvia and Lithuania, which are NATO members.

He pledged that the United States, as a NATO ally, had an “unwavering commitment” to their defense, according to the White House’s account of the call.

In Kiev, Ukraine’s new foreign minister, Andrii Deshchytsia, said that some small progress had been made to form a “contact group” of foreign diplomats to mediate the country’s confrontation with Russia after the occupation of Crimea by Russian soldiers and local “self-defense” groups more than a week ago. Washington has sought to establish the contact group, which would include Russia, Ukraine, Britain, France and the United States, as a way to bring Moscow and Kiev to the negotiating table.

Crimea’s regional assembly voted Thursday to secede from Ukraine and apply to join the Russian Federation, and scheduled a referendum for March 16 to ratify its decision, significantly escalating the crisis between Russia and the West.

Ukraine, along with the United States and Europe, declared the referendum unconstitutional and made clear it would not recognize the vote, though the prospect of Crimea joining Russia received an overwhelmingly positive reaction from Russian lawmakers Friday.

“We have a certain small progress and some hope that we will manage this in a peaceful way,” Deshchytsia said in Kiev. “We need to create some negotiating mechanism” with Russia, “and we think it should be established as soon as possible.” He said Ukraine was open to talks with Russia in any setting “to stop the aggression and de-escalate the situation.”

But Lavrov did not budge from Russia’s position that the new government in Ukraine was illegitimate and under the sway of “radical nationalists” who seized power in a coup. He insisted that any talks with Europe or the United States should begin with the agreement signed Feb. 21 between the ousted Ukrainian president, Viktor Yanukovych, and opposition leaders, even though that accord fell apart almost immediately.

The diplomacy is likely to be complicated, however, because Russian officials have refused to recognize Ukraine’s new political leaders, though the Russian and Ukrainian prime ministers have spoken and Deshchytsia said messages were being exchanged through intermediaries.

In Crimea itself, tensions continued to mount. Poland evacuated its consulate in Sevastopol on Saturday “because of continuing disturbances by Russian forces there,” the country’s foreign minister, Radoslaw Sikorski, said.

There were new reports of Russian military maneuvers Saturday, the morning after Russian troops tried to seize a Ukrainian air force base in the port of Sevastopol. Two Russian military vehicles smashed through the gate of the base, but there were no shots fired and the vehicles withdrew.

“They came here because it was our turn,” said Lt. Col. Andrey Aladashvilli, an officer at the base. “They’ve already been everywhere, they’ve tried to block, seize and establish control everywhere. We’re practically one of the last.”