ROME: US President Joe Biden and his Turkish counterpart Recep Tayyip Erdogan pledged Sunday to improve bilateral ties following a particularly tense period between Washington and Ankara.

Meeting on the sidelines of the G20 summit in Rome, the two leaders "had a very constructive conversation" in which Biden "made clear his desire to have constructive relations with Turkey and to find an effective way to manage our disagreements," a senior US administration official said.

According to the Turkish presidency, "the meeting took place in a positive atmosphere", and the presidents "expressed their joint commitment to further strengthening Turkey-US relations and agreed to establish a joint mechanism to that effect."

They also "stressed the importance of the NATO alliance," the Turkish presidency said.

Turkey's 2019 purchase of a Russian S-400 air defence system has been an irritant on ties, prompting Washington to block Ankara's plans to buy about 100 next-generation US F-35 planes.

Erdogan has insisted on compensation, saying Washington could pay back at least part of the $1.4 billion advance payment Turkey made for the F-35s through the delivery of older-generation F-16 fighter jets.

In addition, Erdogan earlier this month threatened to expel a slew of Western ambassadors, including from the United States, over their support for a jailed Turkish activist.

According to the White House, Biden used the meeting to also raise the issue of human rights, and discuss a "full range of foreign policy topics," including Afghanistan, Syria, Libya, the Eastern Mediterranean, the South Caucasus region -- and climate change.