FRANKFURT, Germany — A union representing striking Lufthansa flight attendants rejected the latest offer from the company Monday as the two sides prepared for more cancellations at the airline’s German hubs.

Union head Nicoley Baublies said the latest offer was only a “minimal” improvement.

Lufthansa said it offered improvements including increasing a one-time signing bonus to 3,000 euros, or about $3,300, from 2,000 euros previously. The company also proposed a summit meeting between union leaders and top management – including CEO Carsten Spohr – to resolve remaining issues on the condition that labor representatives immediately end the strike.

Baublies said union officials would meet Spohr at any time, but “without preconditions.”

The company called the stoppage by the UFO flight attendants union “irresponsible.”

The strike action, launched Friday, is due to last all week, with shifting targets. On Monday, about 113,000 passengers on 929 flights were affected at the Frankfurt, Munich and Duesseldorf airports.

The travel disruptions highlight the pressure Europe’s flagship carriers are under as they struggle to compete with Gulf airlines on long-haul flights between Europe and Asia and with budget brands on regional routes.