The Congress votes to admit new states and territories. So joining another state is probably the only way to get around them saying no to a new state.
"New States may be admitted by the Congress into this Union; but no new State shall be formed or erected within the Jurisdiction of any other State; nor any State be formed by the Junction of two or more States, or Parts of States, without the Consent of the Legislatures of the States concerned"
The Congress votes to admit new states and territories. So joining another state is probably the only way to get around them saying no to a new state.
"New States may be admitted by the Congress into this Union; but no new State shall be formed or erected within the Jurisdiction of any other State; nor any State be formed by the Junction of two or more States, or Parts of States, without the Consent of the Legislatures of the States concerned"