"Taking into account what we know, we are able to talk about a solid and reasonable mandate," Merkel said in a television interview screened on Sunday.

Berlin was scheduled to receive an official request from Lebanon before 11:00 UTC on Sunday before officially announcing the sending of troops.

The German cabinet was due to discuss how many troops it will send on Monday before putting the proposal before the Bundestag, the lower house of parliament, probably on Friday.

Deployment decision expected Friday

According to press reports, Berlin will send anywhere between 1,200 and 3,000 troops as part of the UNIFIL mission to help secure the fragile ceasefire between Israel and the Shiite militia Hezbollah in southern Lebanon.

Merkel has for weeks been saying Germany will not send ground troops in order to eliminate the risk of clashes with Israeli soldiers, which remains a fraught issue because of the country's Nazi past.

However, Germany could take command of the maritime mission charged with intercepting the delivery of arms destined for Hezbollah.

Such an engagement "serves to protect German interests which are in a very difficult situation in the Middle East, which is not that far from us," Merkel said in the interview with "Bericht aus Berlin".

The magazine Focus reported that Germany will decide next week to commit up to 3,000 troops to UNIFIL and that the deployment would be restricted to sea and air troops.

Medics and marines on standby

Sources close to the government said it had already decided to send a 1,200-strong naval force as well as between 200 and 300 military medics.

Saturday's edition of the daily newspaper Tagesspiel reported that the figure will be closer to 2,000 troops with 800 soldiers from the Luftwaffe, Germany's air force for reconnaissance missions.

The paper also reported that the government could contribute two warships, up to four torpedo launchers and six Tornado combat planes.

A defense ministry spokesman told Sunday newspaper Welt am Sonntag that Germany would react once Lebanon had made its request and refused to speculate on the number of German soldiers to be deployed.