"deepen efforts" is correct and usable in written English.
You can use this phrase when referring to increasing or intensifying the efforts in a particular endeavor or task. For example, "We must deepen our efforts to reduce poverty in the region."
We must root out the "bad apples" and deepen efforts to build and maintain properly paid, trained and equipped civil services, in every country, including Cites and enforcement authorities and park rangers.
"Post-Copenhagen, there is a need for stronger cooperation between private enterprise and government, and we'll now deepen efforts at cooperating with regions that control huge procurement budgets and with cities that also really spend money on innovative technologies," he said.
The pre-census measure has been criticised as an attempt to deepen efforts to totally marginalise the one million Rohingya residing in the country, which would be achieved by officially identifying them as foreign interlopers – "Bengalis" – who have no place in Burma and therefore no rights.
Normally the additional deepening effort would require a new and separate dredging permit -- a process that normally takes several years to complete.
The idea was that this would encourage some people to deepen their efforts and others to become new volunteers.
The Obama administration has made clear that it has no desire to deepen its efforts, mostly providing logistical support for the rebels.
Here's a random selection: "A subset of UN Global Compact CEO Water Mandate companies pledge to expand and deepen their efforts in support of more sustainable water management practices in 2012 and beyond".
Rather than imitate Thailand and Indonesia, China could do what Argentina did in 1995: restructure its financial system, deepen the efforts to break up the huge, state-owned industrial firms and do more to open its economy to foreign trade and investment.
In his January 1935 State of The Union Address FDR, also on Dreier's list outlined the ways in which his administration would deepen the efforts begun under the first New Deal, including support for organized labor.
Around the time that BlackBerry deepened its efforts in emerging markets, it also bought QNX Software Systems, whose operating systems powered technology ranging from medical devices to computerized automobile interfaces.
Rather, it complements, magnifies, and deepens reform efforts, activated by and responding to battles already underway at the level of public philosophy, social movements, and local or regulatory reforms.
