The visit of US Senators comes following president-elect Donald Trump's campaign message that US' support for its NATO allies in the case of an attack from another state was conditional and not automatic.
"We wanted to come here for several reasons, and one is to thank the Latvian government and people for their continued friendship and support; for the brave young Latvians that have served in Afghanistan ..." said Senator John McCain.
"Our relationship will not change. We will continue to have strong support for NATO in the Congress of the US and the US Senate.
"Again, the partnership we enjoy with Latvia is important. I believe that it would be very helpful to our relationship to have a permanent US presence here - not as a permanent base but on a rotational basis - that we have continuous American military presence here for training, cooperation and joint operations," said McCain.
Potential new sanctions against Russia
"We believe - the three of us - and most of our colleagues in the US Senate that Vladimir Putin [sic] and Russian behavior is unacceptable, the latest being apparent attempts on the Russian part to affect the outcome of the recent election in the US," said McCain.
"Russia is trying to break the back of democracies all over the world. You're constantly bombarded in Latvia by Russian propaganda and interference in your society. You can expect that the Congress will investigate the Russian involvement in our elections and I predict there will be bipartisan sanctions coming that will hit Russia hard - particularly Putin as an individual," said Senator Lindsay Graham.
"Knowing the relationship between Latvia and Russia you can expect some economic pain. It will be true in America [too]. But freedom is worth suffering pain [for]. It is now time for Russia to understand - enough is enough," said Graham.
None of the three senators visiting have expressed support for the president-elect. Klobuchar is a Democrat senator, while McCain and Graham publicly stated that they won't vote for Trump.
When asked how the senators are sure of whether the US stance won't be different from theirs, McCain said: "My first answer to you is my reputation, which has been made over many years. I've disagreed with other presidents and I've worked with other presidents."
The senators also praised Latvia for its defense spending target to reach 2% of GDP by 2018 and denied that the US could mollify its stance on Russian aggression in Crimea when Trump is president.
The senators have arrived in Latvia as part of a regional visit that includes Georgia, Estonia, Lithuania, Montenegro and Ukraine.