Press Secretary Jen Psaki told reporters the White House was "considering a range of levers, including working through legislation, including executive actions."
The parliamentary leaders were informed that the speaker in consultation with the chairman Senate had decided to constitute the committee comprising the leaders of the parliamentary parties.
"I am happy Balochistan & former FATA got these two slots in line with my policy of mainstreaming those parts of Pak that have been marginalised or left behind in the past," he tweeted.
PTI has fielded Sadiq Sanjrani and Mirza Muhammad Afridi, while the joint opposition has nominated Yousaf Raza Gillani and Maulana Abdul Ghafoor Haideri for post of Senate chairman, deputy.