TALLINN (AFP) - France will offer to send four fighter jets to the Baltic states and Poland to boost Nato air patrols over the region, a source close to the French defence minister said on Friday.

Besides the Rafale and Mirage 2000 aircraft, Paris will also offer to ensure "AWACS patrols from France around twice a week" if asked by Nato, the source said during the minister's visit to the Estonian capital Tallinn amid the Ukraine turmoil.

The AWACS aircraft - Airborne Warning and Control System - are among the most sophisticated planes in the Nato armoury, capable of monitoring huge swathes of airspace.

French Defence Minister Jean-Yves Le Drian will also visit Estonia's fellow Baltic state Lithuania and neighbouring Poland on Friday.

The visit is a bid to reassure "Balts and Poles, Russia's neighbours, given the Ukraine crisis," the source said, adding that the Nato military alliance has assured patrols over the Baltics since 2004.

The United States is responsible for the patrols until May. Given the situation in Ukraine, it sent additional F-15 fighter jets to the region earlier this month, bringing their total to 10 aircraft.

Poland will then take over the patrols from the US. The ministry source said France will offer the fighter jets, along with the AWACS early warning aircraft, if Nato and Poland deem them necessary.

Nato has already deployed AWACS reconnaissance aircraft to overfly Poland and Romania as part of its efforts to monitor the Ukraine crisis.