Whilst more can definitely be said regarding the reactions of the other European "Great Powers" during the 19th century as Russia began expanding and consolidating lands further east, the British Empire was particularly concerned about these maneuvers, and a general Russophobia haunted the foreign policy of many successive governments in Whitehall in the 1800s. This tension between the two countries is often referred to in pop-history narratives as the "Great Game", though recent academic works have rightly moved away from using such a term, as the Russians did not intend to "compete" with the British for influence and resources in the region (or at least, not under the direct orders of St. Petersburg). For more on the reasons behind this reaction and the (perceived) threat it posed to the "Pax Britannica", this older writeup should be of some interest.

For further reading, see Alexander Morrison's The Russian Conquest of Central Asia: A Study in Imperial Expansion 1814 - 1914 (2020), and for Morrison's view on the "Great Game" as a term, see his journal article, Killing the Cotton Canard and getting rid of the Great Game: rewriting the Russian conquest of Central Asia, 1814 - 1895.