"calls for a focus" is correct and usable in written English.
You can use it when you need to emphasize the importance of focusing on something in particular. For example, "This project calls for a focus on the customer experience."
This paper thus calls for a focus on the value of bottom-up territorialization and the ingenious combination of city planning and territorialization to achieve effective urban redevelopment.
This paper evaluates the most influential current approaches to the mechanisms of radicalisation on the basis of their empirical evidence and calls for a focus on research designs capable of arbitrating on matters of causality, not just correlation.
(There is also a spoof campaign ad on the Web in which an actress playing Ms. Warren calls for "a focus on retribution" and promises to push for legislation "that gives every American a revenge voucher").
Among other things, the Roadmap calls for a focus on a limted number of "outcome-driven priorities," cooperation with other agencies and institutions, concentration on both fundamental science and extension, and a "rejuvenation" of the USDA competitive grant system.
The town has just completed a strategic plan that calls for a focus on entertainment-related businesses in the area around the stadium, which could include everything from restaurants to sports centers or an Imax theater, he said.
This evidence strongly calls for a focus on educational outcomes, not just attainment.
This calls for a focused analysis, in order to evaluate whether conditions exist for its wide employment.
The administration also called for a focus on manufacturing because of its spillover effects on the economy.
Several liberal Catholic groups held news conferences outside the bishops' meeting, calling for a focus on poverty and economic injustice.
The British Legion is this year calling for a focus on the "future of the living" and the "memory of the fallen".
