UPDATE 1-U.S. House panel to force testimony from Trump's Afghan envoy

The U.S. House of Representatives Foreign Affairs Committee said on Thursday it will subpoena President Donald Trump's special Afghanistan envoy, Zalmay Khalilzad, to testify on Sept. 19, after the abrupt cancellation of talks with the country's Taliban militia. Representative Eliot Engel, the committee's Democratic chairman, said he signed the subpoena after the U.S. State Department ignored numerous requests for briefings by Khalilzad about the Afghanistan peace plan and the administration's path forward in that country.

Engel released a letter last week expressing frustration with the administration's failure to arrange briefings by Khalilzad. He said the State Department had refused requests in February, April and earlier this month for briefings or testimony. The State Department did not immediately respond to a request for comment on the subpoena.

Trump proclaimed negotiations with Afghanistan's Taliban leaders dead on Monday after scrapping talks with the group planned for Camp David, Maryland, during the weekend after a U.S. soldier was killed by a suicide bomber in Kabul. The abrupt announcement - and news that Trump had planned to bring Taliban leaders to the American presidential retreat - angered many in Congress.

Bringing U.S. troops home from Afghanistan has been one of Trump's main foreign policy objectives, and the Republican president said his administration was still thinking about a drawdown of the 14,000 U.S. soldiers in the country. It was the first subpoena issued by the committee since Democrats took control of the House in January and Engel became chairman.