KIEV, Ukraine — In a demonstration of support for Ukraine’s fledgling government and a new swipe at Russia, Secretary of State John Kerry visited Kiev on Tuesday with an offer of $1 billion in an American loan guarantee and pledges of technical assistance.

Trudging through a damp mist, Mr. Kerry stopped first for an emotional visit to improvised memorials where protesters were gunned down last month as they voiced opposition to what was then Ukraine’s pro-Kremlin government.

Mr. Kerry placed a lighted candle at one of the shrines, which were draped with flowers and photographs of some of the victims; met with religious leaders; and listened to Ukrainians who beseeched him for help.

“We hope Russian troops will leave Crimea, and we also hope for your assistance,” a Ukrainian woman told Mr. Kerry as he walked along Instytutska Street.