WASHINGTON The United States is seeking a six-month extension to a science and technology agreement with China so that it can undergo negotiations with Beijing to "amend and strengthen" the landmark deal, the State Department said on Wednesday.

For over 40 years, the agreement between the two countries has yielded cooperation across a range of scientific and technical fields, a powerful sign that the rivals could set aside their disputes and work together.

It is due to expire on Aug. 27.

"This short-term six-month extension will keep the agreement in force while we seek authority to undertake negotiations to amend and strengthen the terms of the STA (Science and Technology Agreement). It does not commit the United States to a longer-term extension," a department spokesperson told Reuters.

(Reporting by Michael Martina)