Washington: The US State Department issued a travel advisory on Sunday warning Americans not to travel to Russia due to mounting tensions on the border with Ukraine. “Do not travel to Russia due to ongoing tension along the border with Ukraine,” a statement said, adding Americans could also face “harassment” and that the embassy would have “limited ability to assist US citizens.” It particularly moved to dissuade US citizens from traveling to the Russia-Ukraine border region, saying “the situation along the border is unpredictable and there is heightened tension,” due to a Russian troop build-up and military exercises in the area.