TEHRAN, Iran — The mothers of three jailed Americans brought appeals for their freedom to Iran on Wednesday on a mission that could be complicated by diplomatic showdowns over the country’s nuclear program.

The three women will visit their children — who have been held since July when they were arrested along the Iraqi border — and seek meetings with top Iranian officials. Iran’s state-run Press TV said the weeklong visas had been granted on an “Islamic humanitarian basis.”

Nora Shourd, Cindy Hickey and Laura Fattal wore long black head scarves and passed through routine customs and passport checks as well being fingerprinted — a requirement imposed on Americans in retaliation for U.S. immigration controls on Iranians.