Washington - US senators visiting eastern European allies to discuss security issues called for sanctions against Russia for interfering in the presidential election by hacking American political sites and email accounts. Their demands came amid ongoing discussions among US officials on an imminent response that would ensure the US takes action against Russia before president-elect Donald Trump takes office."We have to sanction Russia for these cyber attacks [and] send a clear message to the incoming administration that there is a lot of bipartisan support in Congress for going after this," Senator Amy Klobuchar told The Associated Press by phone from Latvia.Klobuchar joined Senators John McCain and Lindsey Graham in their visits to some of Russia's neighbours - the Baltic states, Ukraine and Georgia - as well as Montenegro.Russian officials have denied the Obama administration's accusation that the highest levels of the Russian government were involved in trying to influence the US presidential election. US intelligence agencies concluded that Russia's goal was to help Trump win - an assessment Trump has dismissed as ridiculous.The Obama administration has said the US will respond at a time and with a means of its choosing, and that all responses may not be publicly known.The lawmakers on Wednesday reaffirmed the US commitment to the Baltics, saying the relationship with the three former Soviet states - Estonia, Latvia and Lithuania - "will not change" under the new administration."I predict there will be bipartisan sanctions coming that will hit Russia hard, particularly [President Vladimir] Putin as an individual," Graham told reporters in Riga, the Latvian capital. He didn't elaborate on possible sanctions.The US has already sanctioned Russia over its annexation of Crimea and the conflict in Ukraine, but it could potentially use an April 2015 executive order allowing for the use of sanctions to combat cyber attacks.A year after the order was issued, Democratic Party officials learned their systems were attacked after discovering malicious software on their computers.The order covers a response to attacks on critical infrastructure and Klobuchar called on the administration to amend it to include election systems. And while Trump could change back any amended or new order allowing for the US to impose sanctions on entities involved in a cyber attack on election systems, "he would have a lot of explaining to do", Klobuchar said. "The executive order gives tools to respond." Speaking to journalists on Wednesday, Trump was not addressing the issue of sanctions, but said: "We don't have the kind of security we need." He added: "Nobody knows what's going on."President Barack Obama has ordered intelligence officials to conduct a broad review of the election-season cyber attacks. Russia's neighbours have long suffered the wrath of its hackers, whose actions have frequently complemented Moscow's political and military aims. In 2014, Ukraine's Central Election Commission was targeted by a pro-Russian hacking group.