Not exclusively. I am in the US and I believe I consistently put primary stress on the second syllable. Merriam-Webster (an American English oriented dictionary) gives both pronunciations, but lists the first-syllable-stress version first: https://www.merriam-webster.com/dictionary/anchovy

Yes, and I'll also note that the secondary stress seems to be on the second syllable. That is, the second syllable is not reduced like in the UK. So it's pronounced most commonly in the US more like "Anne Chovy" than "Anchvy"