A key House panel on Thursday approved a bill that would increase funding by at least $60 million for a homeland missile defense system.

The chamber's Armed Services Committee in a unanimous vote just after midnight approved annual defense authorization legislation that included a number of missile defense-related measures, such as $20 million in funding to begin constructing a third domestic interceptor site. The bill also includes an extra $40 million for the Ground-Based Midcourse Defense system.

The Defense Department did not seek funding in its fiscal 2015 budget request for construction of a third interceptor site. The Pentagon is currently studying possible locations for the site on the East Coast. The department has not yet decided if it will move forward with building the facility, which is a favored defense project for Republicans who are concerned about a possible missile attack by Iran.

The two existing interceptor sites in the country are located in Alaska and California and are part of the Ground-Based Midcourse Defense system, which is under heavy scrutiny due to a string of expensive intercept test failures. The Pentagon had requested just over $1 billion for the program for the coming fiscal year. However, the Republican-led HASC panel chose to boost that figure by $40 million, according to the draft bill text.

The legislation also includes language that would hasten the deployment of U.S. missile defenses in Poland. An amendment introduced by U.S. Representative Mike Turner (R-Ohio) and approved by the committee would require the Pentagon to activate no later than the end of 2016 an Aegis Ashore system in the Eastern European country. Poland has already agreed to host an Aegis interceptor facility as part of the Obama administration's "Phased Adaptive Approach" for European missile defense, but that site is currently not planned to go online before the 2018-to-2020 timeframe.

Republicans in the Senate have introduced their own bill that would require the administration to study options for speeding up activation of the Polish missile interceptor site by the end of 2016.

But 2016 is not soon enough for Turner for achieving an operational antimissile capacity in Poland. In addition to accelerating the timetable for standing up the planned Aegis site, his amendment would require the U.S. military by the end of this year to field a "short-range air and missile defense capability or terminal missile defense capability, or both, and the personnel required to operate and maintain such [a] system" in the NATO-allied nation.

The House floor is anticipated to take up the defense authorization bill during the week of May 19, according to the Center for Arms Control and Nonproliferation, which tracks congressional actions related to nuclear weapons and missile defense. The Senate Armed Services Committee plans to begin writing its own version of the bill on May 20.