- Associated Press - Saturday, April 26, 2014

DALLAS (AP) - Russia certainly has the capability to invade eastern Ukraine, the chairman of the Joint Chiefs of Staff said Saturday, but added that he hasn’t determined yet whether the nation’s intent is to do so.

U.S. Gen. Martin E. Dempsey told The Associated Press after a military symposium in Dallas that he found it “unsettling” that Russia would amass forces along the Ukrainian border and deploy Russian aircraft into Ukrainian airspace to influence its May 25 presidential election.

“They are clearly trying to pressure the upcoming elections, and whatever transitional government might form, using military force,” he said.

Dempsey had “grave concern” over Russia’s aggressive behavior, according to an earlier statement issued by the Pentagon.

A German-led group of military observers traveling under the auspices of the Organization for Security and Cooperation in Europe remained in captivity Saturday, accused of being NATO spies by a pro-Russian insurgency.

Dempsey said he told his Russian counterpart, Gen. Valery V. Gerasimov, in a telephone conversation last week that the observers could help stabilize the situation in Ukraine.

“We’ve got observers from the OSCE, some of whom have been denied access by pro-Russian groups, and I suggested to him that one way we could contribute to some kind of stable outcome would be if he on his side and me on my side could seek to get those observers in there so that we could have a neutral party tell us what’s going on,” he said.

Dempsey refuted Gerasimov’s reported assertion by Russia’s Interfax news agency that Ukraine has mobilized a “significant number of troops” on the Ukrainian side of the border with Russia.

“That’s not at all what our reports indicate is unfolding in Ukraine,” he said.

Nevertheless, outside Slovyansk, a city about 150 kilometers (90 miles) west of Russia, Ukraine government forces continued operations to form a security cordon as it attempts to quell unrest threatening to derail the planned May election.

The West has threatened additional sanctions against Russia over its annexation of Crimea from Ukraine in March and the ongoing escalation of military operations along the border.