Renowned cellist Yo-Yo Ma, a US citizen born in France of Chinese parents, told a congressional committee on Tuesday that “the high financial cost, uncertain timeline and countless logistical hurdles” involved in obtaining US visas for foreign artists meant that cultural exchanges were becoming less frequent.

The House government reform committee was told that since new restrictions were imposed following the September 11 2001 attacks, delays in obtaining visas had caused the number of foreign artists performing in the US to drop.