WASHINGTON (AP) — An influential Republican senator says he'll withhold approval of U.S. weapons sales to several Middle Eastern allies until there is a clear path for settling a diplomatic crisis with Qatar (KUH'-tur).

In a letter delivered Monday, Sen. Bob Corker of Tennessee tells Secretary of State Rex Tillerson that "recent disputes" among members of the Gulf Cooperation Council undermine efforts to combat the Islamic State and counter Iran.

Corker is the chairman of the Foreign Relations Committee.

The council is an alliance of six Middle Eastern countries, including Qatar, Saudi Arabia, the United Arab Emirates, and Bahrain.

Riyadh, along with the UAE, Bahran and Egypt cut ties with Qatar over allegations that it funds terrorism. Doha rejected the accusation. But the move has left Qatar effectively blockaded by its Arab neighbors.