Given the following context:

By far the most significant factor that led to the princes' decision to accede to India was the policy of the Congress and, in particular, of Patel and Menon. The Congress' stated position was that the princely states were not sovereign entities, and as such could not opt to be independent notwithstanding the end of paramountcy. The princely states must therefore accede to either India or Pakistan. In July 1946, Nehru pointedly observed that no princely state could prevail militarily against the army of independent India. In January 1947, he said that independent India would not accept the divine right of kings, and in May 1947, he declared that any princely state which refused to join the Constituent Assembly would be treated as an enemy state. Other Congress leaders, such as C. Rajagopalachari, argued that as paramountcy "came into being as a fact and not by agreement", it would necessarily pass to the government of independent India, as the successor of the British.Patel and Menon, who were charged with the actual job of negotiating with the princes, took a more conciliatory approach than Nehru. The official policy statement of the Government of India made by Patel on 5 July 1947 made no threats. Instead, it emphasised the unity of India and the common interests of the princes and independent India, reassured them about the Congress' intentions, and invited them to join independent India "to make laws sitting together as friends than to make treaties as aliens". He reiterated that the States Department would not attempt to establish a relationship of domination over the princely states. Unlike the Political Department of the British Government, it would not be an instrument of paramountcy, but a medium whereby business could be conducted between the states and India as equals.

answer the following question:

Who declared that any princely state which refused to join the Constituent Assembly would be treated as an enemy state 

Nehru