KIEV, March 18 - Ukraine has strengthened frontier defenses with Russia following Moscow's seizure of Crimea but there is no sign of a major troop build-up in a region where some say they would welcome a Russian takeover, Reuters reported.

On a day when a Ukrainian soldier became the first fatal casualty in the confrontation on the Black Sea peninsula, at the southernmost crossing between the two countries, where Ukraine dug anti-tank ditches this week, Kiev's frontier guards were keen to play down the Russian threat and hope for the best.